Setting grid to Triplets?

Is there any way to set the grid markers to triplets? I have been doing a lot of drum editing by slipping the audio in the regions.

If there isn’t a way, is there a way to make a feature request for this. I know a lot of drum editors that would absolutely love this feature.

No.
Use a blank midi track, set the grid to whatever note division you want, toggle in place editor. That’s the only work around I know of.