Question: `am_addons` flag not set

[s373nZ]

I'm experimenting with building an addon and running the Gnuton fork on a DSL-AX82U (thanks, love it!).

Merlin's addons API documentation shows an example of checking for firmware addons support in the installer script:

# Does the firmware support addons?
nvram get rc_support | grep -q am_addons
if [ $? != 0 ]
then
    logger "MyPage" "This firmware does not support addons!"
    exit 5
fi

However, this flag isn't set on my router. Research suggests it's set at compile time? It seems perfectly possible to ignore this flag in an implementation, but I would like to reconcile with the upstream documentation if possible and am just generally curious. I'm wondering if Gnuton builds should include the flag, or if the author has any feedback. Thanks!