Renju Wiki: en.wikipedia.org/wiki/Renju
Gomoku Wiki: en.wikipedia.org/wiki/Gomoku

Will likely use the Go board, but adjusted ro 15x15 with no captures and swap option (if able)

I think the most tricky addition will be Forbidden Moves (Renju wiki)

I'd ask Play strategy to consider adding this addition!
There are more resources on the Renju federation page.