https://mariussilaghi.com/products/quad-cap-pro

Quad Cap Pro is a modifier plugin for 3ds Max that fills borders and ngons with quad polygons unlike the normal cap tool which produces one big ngon.
Quad Cap Pro is the successor of the Quad Cap maxscript. It is now faster, has many more features and also it can cap ngons with an uneven number sides producing quads and a single triangle