It looks like a useful assertion to have after the mem leak fix: https://cgit.freebsd.org/src/commit/?id=0626d30e41cba64b41667314c3a4f7611f0eb685. It could flag still existing or new mem leak issues.
As long as the only armv7 I have is qemu-system-arm -M virt it was a long journey to get the tests passed on my side due to several obstacles:
- vtnet unaligned read panic. There are several patches around, now it's integrated to main: https://cgit.freebsd.org/src/commit/?id=3be59adbb5a2ae7600d46432d3bc82286e507e95
- if_epair unaligned read panic. A similar to the first one, resolved by my quick patch.
- Netlink defect and pfctl regression as a result. Resolved by https://cgit.freebsd.org/src/commit/?id=0c511bafdd5b309505c13c8dc7c6816686d1e103.
I've managed to run most of the pf tests and have not faced panics related to these two assertions. Especially the tests which create a deep structure of anchors, etc.
In order to run all pf tests I would need to deal with unaligned reads at other places (e.g. in6 related). But, probably, this patch can already be found useful during pf related development for still supported armv7.