diff --git a/ports/atmel-samd/Makefile b/ports/atmel-samd/Makefile
index 3da3790623..48724af0c8 100644
--- a/ports/atmel-samd/Makefile
+++ b/ports/atmel-samd/Makefile
@@ -150,13 +150,7 @@ else
   CFLAGS += -flto -flto-partition=none
 
   ifeq ($(CIRCUITPY_FULL_BUILD),0)
-    # Increasing max-inline-insns-auto from 20 to 1000 gains about 300 bytes on a small build.
-    CFLAGS += --param inline-unit-growth=15 --param max-inline-insns-auto=1000
-    # These optimizations are normally -O3 only. They improve the way register
-    # allocation is done, but, to quote the gcc doc, 'can, however, make debugging impossible,
-    # since variables will no longer stay in a “home register”.'
-    # On a small build they can gain about 200 bytes.
-    CFLAGS += -fweb -frename-registers
+    CFLAGS += --param inline-unit-growth=15 --param max-inline-insns-auto=20
   endif
 
   ifdef CFLAGS_BOARD
diff --git a/ports/atmel-samd/boards/meowmeow/mpconfigboard.mk b/ports/atmel-samd/boards/meowmeow/mpconfigboard.mk
index 175501313e..8ee9d23fe5 100644
--- a/ports/atmel-samd/boards/meowmeow/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/meowmeow/mpconfigboard.mk
@@ -14,3 +14,4 @@ CIRCUITPY_COUNTIO = 0
 CIRCUITPY_RTC = 0
 
 SUPEROPT_GC = 0
+SUPEROPT_VM = 0
diff --git a/ports/atmel-samd/boards/pewpew_m4/mpconfigboard.mk b/ports/atmel-samd/boards/pewpew_m4/mpconfigboard.mk
index 1614779684..99dddfa892 100644
--- a/ports/atmel-samd/boards/pewpew_m4/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/pewpew_m4/mpconfigboard.mk
@@ -25,6 +25,7 @@ CIRCUITPY_ROTARYIO = 0
 CIRCUITPY_RTC = 0
 CIRCUITPY_SAMD = 0
 CIRCUITPY_TOUCHIO = 0
+CIRCUIPTY_USB_CDC = 0
 CIRCUITPY_USB_HID = 0
 CIRCUITPY_USB_MIDI = 0
 CIRCUITPY_VECTORIO = 0
@@ -40,12 +41,5 @@ CIRCUITPY_STAGE = 1
 FROZEN_MPY_DIRS += $(TOP)/frozen/circuitpython-stage/pewpew_m4
 CIRCUITPY_DISPLAY_FONT = $(TOP)/ports/atmel-samd/boards/ugame10/brutalist-6.bdf
 
-# Tweak inlining depending on language.
-ifeq ($(TRANSLATION), zh_Latn_pinyin)
-RELEASE_NEEDS_CLEAN_BUILD = 1
-CFLAGS_INLINE_LIMIT = 45
-else
-CFLAGS_INLINE_LIMIT = 70
-endif
 # Override optimization to keep binary small
 OPTIMIZATION_FLAGS = -Os
diff --git a/ports/atmel-samd/boards/trinket_m0/mpconfigboard.mk b/ports/atmel-samd/boards/trinket_m0/mpconfigboard.mk
index 6595fa164d..fbbb974cdf 100644
--- a/ports/atmel-samd/boards/trinket_m0/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/trinket_m0/mpconfigboard.mk
@@ -12,3 +12,6 @@ CIRCUITPY_FULL_BUILD = 0
 
 SUPEROPT_GC = 0
 SUPEROPT_VM = 0
+
+# On this particular board, these save about 180 bytes. On other boards, they may -increase- space used.
+CFLAGS_BOARD = -fweb -frename-registers