Can/should you delete render files in the Finder or only inside FCP?

Was making space and wondered if deleting render files from the finder (Library>show package) would be harmful vs. usual way from inside of FCP. Thanks.

Inside FCP is always best, or use Final Cut Library Manager from ArtcicWhitness. Even though I'm very comfortable with poking around in the Library package contents, I avoid it as much as possible. Accidents happen, and an accident inside that package could be disastrous.
www.arcticwhiteness.com/finalcutlibrarymanager/

Thanks, I figured. It just seemed it'd be easier to do in the finder while I was in there.

Wondering wrote: Was making space and wondered if deleting render files from the finder (Library>show package) would be harmful vs. usual way from inside of FCP. Thanks.

What Ben said is correct. However if you use the library inspector Storage Locations>Modify Settings>Cache and designate an external folder to store the cache files, those are easier and safer to delete in Finder.

That is because they are all within a single bundle -- separate from the library. The cache bundle includes thumbnails, waveforms, optical flow analysis files and render cache. The entire bundle can be deleted. I normally do that  when FCP is shut down.

But (as Ben said) the best solution is using Final Cut Library Manager -- especially if you have many libraries. Instead of treating each one separately, it scans them all and allows taking collective action on all.