Fixing Tacky Resin on Coaster

I went to take my latest resin coaster out of it’s mould today – whilst the majority of the project is set, some parts of it are still tacky and have become warped and dimpled.

I have read that I can try to scrape off the wet parts, sand it and put on another coat of mixed resin, however I’m unsure how this works with a mould? The coaster has a raised edge, so I’m unsure how I would coat the whole thing, 1.) without disturbing the shape of the coaster, and 2.) if it’s possible to fix it using the mould, and how I would go about doing so?

Any help would be greatly appreciated! Thank you!