I do the same with Prismacolor pencils on matte FB paper. I blend mine with turpentine + vegetable oil mixture, so it's about the same process.
I typically wait overnight before framing. Sometimes, additional oil comes to surface and require LIGHT buffing by dry cotton pads.
I let it sit over a month before just to see what happens but after the initial drying which basically is turpentine evaporating, it doesn't seem to change much at all. The surface remain delicate. If I have to store it somewhere, I cover it with paper. One thing I learned NOT to do is to let anything like plastic touch the surface. The precipitating oil will do a number on it.