Alright, that was incredibly helpful, very quick and easy to debug; it seems the issue was specifically related to Blueprint Sandbox, and the way they were handling the deconstruction planner when in the sandbox.
I have the list of recyclers listed per surface and checked on a certain timer for the auto-ingredient push, and whenever one is removed in some way, they also need to be removed from the list, so I have checks for when they are mined by player, deconstructed by bot, and destroyed from damage (the standard vanilla methods), but there's also a custom script-based "destroy" command that I didn't account for, so the mod was checking for an entity that no longer existed.
Glad to know that all my custom surface code was actually working perfectly; all I had to do was add another check for that possibility, and should be fixed as of 8.2.7!