Sorry for the very late response. Most instances don't allow such large image uploads, rimworld.gallery renders can be up to 30MB. But still, thumbnails should be shown instead of the full image
You can disable it in the mod settings, so you'll have it ready for your next run (it will auto-enable when you start a new map). In the mean time, you can make a fancy render to post on rimworld.gallery
What stops you from adding it now? It's safe to add mid game.
RimWorldPorn on lemmy.world: https://lemmy.world/c/[email protected]
RimWorldPorn on rimworld.gallery: https://rimworld.gallery/m/rwp (you can find it on your own instance under magazines)
To upload a render you need to log on to rimworld.gallery due to filesize restrictions on most fediverse instances