License question

[fotisandstuff]

Hello! I would like to have the Submarine Free modules ported to the VCV fork Cardinal. However, they only allow modules which are licensed under "GPL 3.0-or-later", not "GPL 3.0-only." More info here.

Submarine Free's license is GPL 3.0 but doesn't clarify if it's "only 3.0" or "3.0 or later". If it's the former, could you please update the license so that they can be ported to Cardinal? Thank you very much.