{build.system.path}

[JAndrassy]

now when system folder is used, the {runtime.platform.path}/system path in platform.txt can be replaced with {build.system.path}

from https://arduino.github.io/arduino-cli/0.33/platform-specification/ :

Moreover the following properties are automatically generated:

• {build.core.path}: The path to the selected board's core folder (inside the core platform, for example hardware/arduino/avr/core/arduino)
• {build.system.path}: The path to the core platform's system folder if available (for example hardware/arduino/sam/system)
• {build.variant.path}: The path to the selected board variant folder (inside the variant platform, for example hardware/arduino/avr/variants/micro)

[earlephilhower]

I believe on a release all the instances of {r.p.p}/system are removed:

arduino-pico/package/build_boards_manager_package.sh

Lines 106 to 128 in 0f437e4

	cat $srcdir/platform.txt | \
	sed 's/^runtime.tools.pqt-.*.path=.*//g' | \
	sed 's/^tools.uf2conv.cmd=.*//g' | \
	sed 's/^#tools.uf2conv.cmd=/tools.uf2conv.cmd=/g' | \
	sed 's/^tools.uf2conv.network_cmd=.*//g' | \
	sed 's/^#tools.uf2conv.network_cmd=/tools.uf2conv.network_cmd=/g' | \
	sed 's/^tools.picoprobe.cmd=.*//g' | \
	sed 's/^#tools.picoprobe.cmd=/tools.picoprobe.cmd=/g' | \
	sed 's/^tools.picoprobe_cmsis_dap.cmd=.*//g' | \
	sed 's/^#tools.picoprobe_cmsis_dap.cmd=/tools.picoprobe_cmsis_dap.cmd=/g' | \
	sed 's/^tools.picotool.cmd=.*//g' | \
	sed 's/^#tools.picotool.cmd=/tools.picotool.cmd=/g' | \
	sed 's/^tools.picodebug.cmd=.*//g' | \
	sed 's/^#tools.picodebug.cmd=/tools.picodebug.cmd=/g' | \
	sed 's/^discovery.rp2040.pattern=.*//g' | \
	sed 's/^#discovery.rp2040.pattern=/discovery.rp2040.pattern=/g' | \
	sed 's/^pluggable_discovery.rp2040.pattern=.*//g' | \
	sed 's/^#pluggable_discovery.rp2040.pattern=/pluggable_discovery.rp2040.pattern=/g' | \
	sed 's/^tools.uf2conv-network.cmd=.*//g' | \
	sed 's/^#tools.uf2conv-network.cmd=/tools.uf2conv-network.cmd=/g' | \
	sed "s/version=.*/version=$ver/g" |\
	sed -E "s/name=([a-zA-Z0-9\ -]+).*/name=\1($ver)/g"\
	> $outdir/platform.txt

For the git version, if you want to use the non-IDE installed versions of the tools I am pretty sure we still need the path as-is.

Are you seeing any issues with the current setup?