diff --git a/keyboards/planck/keymaps/cbbrowne/Makefile b/keyboards/planck/keymaps/cbbrowne/Makefile
index 581e08cd0..b1c70ace7 100644
--- a/keyboards/planck/keymaps/cbbrowne/Makefile
+++ b/keyboards/planck/keymaps/cbbrowne/Makefile
@@ -5,8 +5,8 @@
 #   the appropriate keymap folder that will get included automatically
 #
 BOOTMAGIC_ENABLE = no       # Virtual DIP switch configuration(+1000)
-MOUSEKEY_ENABLE = yes       # Mouse keys(+4700)
-EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
+MOUSEKEY_ENABLE = no       # Mouse keys(+4700)
+EXTRAKEY_ENABLE = no       # Audio control and System control(+450)
 CONSOLE_ENABLE = no         # Console for debug(+400)
 COMMAND_ENABLE = yes        # Commands for debug and configuration
 NKRO_ENABLE = yes            # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
@@ -16,10 +16,11 @@ AUDIO_ENABLE = yes           # Audio output on port C6
 UNICODE_ENABLE = no         # Unicode
 BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
 RGBLIGHT_ENABLE = no        # Enable WS2812 RGB underlight.  Do not enable this with audio at the same time.
+API_SYSEX_ENABLE = yes      # Enable SYSEX API (+5390)
 
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
 ifndef QUANTUM_DIR
 	include ../../../../Makefile
-endif
\ No newline at end of file
+endif
diff --git a/keyboards/planck/keymaps/cbbrowne/config.h b/keyboards/planck/keymaps/cbbrowne/config.h
index 1e04ba61d..bd15fd5a2 100644
--- a/keyboards/planck/keymaps/cbbrowne/config.h
+++ b/keyboards/planck/keymaps/cbbrowne/config.h
@@ -1,6 +1,9 @@
 #ifndef CONFIG_USER_H
 #define CONFIG_USER_H
 
+#define NO_DEBUG
+#define NO_PRINT
+
 #include "../../config.h"
 
 #define LEADER_TIMEOUT 300
diff --git a/keyboards/planck/keymaps/cbbrowne/keymap.c b/keyboards/planck/keymaps/cbbrowne/keymap.c
index 7f1601af7..2be4dab4b 100644
--- a/keyboards/planck/keymaps/cbbrowne/keymap.c
+++ b/keyboards/planck/keymaps/cbbrowne/keymap.c
@@ -62,6 +62,7 @@
    - How about Alt-F1 thru Alt-F8?
    - What's the keystroke to get from X to console these days?
    - A layer for doing console switching would not be a bad idea
+   - I haven't got page-up/page-down, let's have that...
 */
 
 enum layers {
@@ -94,6 +95,7 @@ enum macro_id {
 #define SHIFTQUOTE MT(MOD_RSFT, KC_QUOT)
 #define ALTRIGHT MT(MOD_LALT, KC_RGHT)
 #define MVERSION M(M_VERSION)
+#define ALTSLASH LALT(KC_SLSH)
 
 
 /* Note that Planck has dimensions 4 rows x 12 columns */
@@ -109,14 +111,14 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 [_RAISE] = { /* RAISE */
   {KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_BSPC},
   {_______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_MINS, KC_EQL,  KC_LBRC, KC_RBRC, KC_BSLS},
-  {_______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  QWERTY,  KEYPAD,  KEYPAD,  RESET,   _______},
-  {_______, _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY}
+  {_______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  QWERTY,  KEYPAD,  KEYPAD,  ALTSLASH,_______},
+  {_______, _______, _______, _______, _______, _______, _______, _______, KC_PGDN, KC_VOLD, KC_VOLU, KC_PGUP}
 },
 [_LOWER] = { /* LOWER */
   {KC_TILD, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_BSPC},
   {_______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE},
-  {_______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  QWERTY,  KEYPAD,  KEYPAD, RESET,   _______},
-  {_______, KEYPAD, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY}
+  {_______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  QWERTY,  KEYPAD,  KEYPAD, ALTSLASH,   _______},
+  {_______, KEYPAD, _______, _______, _______, _______, _______, _______, KC_PGDN, KC_VOLD, KC_VOLU, KC_PGUP}
     },
 [_KEYPAD] = { /* Key Pad */
   {KC_ESC,  USERNAME,    MVERSION,   KC_F10,   KC_F11,  KC_F12,   KC_PGUP, KC_KP_ENTER, KC_7, KC_8, KC_9, KC_BSPC},
diff --git a/readme.md b/readme.md
index a92ae4c1d..afdb03ba5 100644
--- a/readme.md
+++ b/readme.md
@@ -348,6 +348,10 @@ This allows you output audio on the C6 pin (needs abstracting). See the [audio s
 
 Use this to debug changes to variable values, see the [tracing variables](#tracing-variables) section for more information.
 
+`API_SYSEX_ENABLE`
+
+This enables using the Quantum SYSEX API to send strings (somewhere?)
+
 ### Customizing Makefile options on a per-keymap basis
 
 If your keymap directory has a file called `Makefile` (note the filename), any Makefile options you set in that file will take precedence over other Makefile options for your particular keyboard.
@@ -1318,14 +1322,30 @@ You probably don't want to "brick" your keyboard, making it impossible
 to rewrite firmware onto it.  Here are some of the parameters to show
 what things are (and likely aren't) too risky.
 
-- If a keyboard map does not include RESET, then, to get into DFU
+- If your keyboard map does not include RESET, then, to get into DFU
   mode, you will need to press the reset button on the PCB, which
-  requires unscrewing some bits.
+  requires unscrewing the bottom.
 - Messing with tmk_core / common files might make the keyboard
   inoperable
 - Too large a .hex file is trouble; `make dfu` will erase the block,
   test the size (oops, wrong order!), which errors out, failing to
-  flash the keyboard
+  flash the keyboard, leaving it in DFU mode.
+  - To this end, note that the maximum .hex file size on Planck is
+    7000h (28672 decimal)
+```Linking: .build/planck_rev4_cbbrowne.elf                                                            [OK]
+Creating load file for Flash: .build/planck_rev4_cbbrowne.hex                                       [OK]
+
+Size after:
+   text    data     bss     dec     hex filename
+      0   22396       0   22396    577c planck_rev4_cbbrowne.hex
+```
+  - The above file is of size 22396/577ch, which is less than
+    28672/7000h
+  - As long as you have a suitable alternative .hex file around, you
+    can retry, loading that one
+  - Some of the options you might specify in your keyboard's Makefile
+    consume extra memory; watch out for BOOTMAGIC_ENABLE,
+    MOUSEKEY_ENABLE, EXTRAKEY_ENABLE, CONSOLE_ENABLE, API_SYSEX_ENABLE
 - DFU tools do /not/ allow you to write into the bootloader (unless
   you throw in extra fruitsalad of options), so there is little risk
   there.