In my project, I use exotic wood to make coasters. The coasters are laser engraved, a process which releases and scorches the natural wood oil.
I sand down all the burn marks leaving a smooth surface. The engravings are filled with colored resin, it works well. The rest of the surface is sealed with a lacquer based sanding sealer and smoothed down again.
The next step is to seal the whole lot with a clear resin coat. And this is where I struggle as there are plenty of fish eyes. Should I rather skip the sanding sealer and leave the wood rough, or will the wood oil also re-act with the resin?
It sounds like you may be using a resin that doesn’t have enough surface tension to want to stay even on the surface. I would suggest using a thicker mixing (doming) resin. If you are already doing that and getting fish eyes, you may need to create a tape dam around your coasters. Pour the resin, then remove the tape after casting.
I would avoid not sanding as I am concerned the oil would act as a mold release.