You can submit it I think.
If it’d been finished & released a few years prior and you hadn’t made any changes to it since, then I’d encourage you to go back and make some revisions before submitting it.
Gaiden magic is compatible with skill systems, but only through the buildfile. Febuilder’s patch of skill systems is about a year and a half old at this point and I don’t think 7743 wants to update it. It works and has very few bugs, which is the important thing to him.
Skill systems buildfile gaiden magic still has some bugs that I just discovered, but it not febuilder friendly at this point.