Your Question

Could the Supplementaries license be changed to clarify the status of addons?

Detail

As of now, Version 1.3 of the Supplementaries License defines

Compete refers to any project or software offering similar functionality, features, or services as the Software and targeting the same or a similar user base. This includes, but is not limited to, software that directly substitutes or mirrors one or more functionalities of the Software.

This, as far as I understand, could define addons for Supplementaries (even compatibility addons) as "competing" with it, since they might directly substitute or mirror functionality from Supplementaries. For example, the golden candle holders from SupplementariesSquared are mirroring a functionality (regular candle holders) from Supplementaries.

Therefore, adding clarification for addons or maybe even changing the definition of "Compete" in the license to exclude software that has a hard dependency on Supplementaries would be appreciated.

(Not related to this, but I noticed articles 4 and 5 are listed in reverse order in the current license, that should also get fixed)

I can write it so it's even clearer. Any addon is obviously allowed as by nature add-ons don't compete as they require the mod itself to be there first to begin with. Competing clause is there to prevent singular features of the mod to be redistribute as standalone offering an alternative that doesn't involve getting the source material