I bought one of those passively cooled router boxes from AliExpress and have been running opnsense for over a year on it now. It’s way overkill for router + ad blocking, but it’s been working great.
What’s the thermostat controlling? How is it wired up? I replaced mine with ram esphome with a temp sensor and a relay that bridges the pins when it wants to turn on. Mine is connected to home assistant but i think you can use esphome devices stand alone.
You can change the support top layer settings and mess with if there is top layers and how many there are, then adjust the gap between support top layer and the first layer of the print on top of it until it’s supported correctly and comes away easily.
The only reason I want it on the router is if either my vm or my server go down for whatever reason I have no access. My router is way overkill hardware wise (it’s running opnsense and Adblocking and I’ve never seen above 2%) cpu usage.
My zfs cache for 6x 4tb drives in raidz2 is about 10gb of ram.
Bend the end of a zip tie into a U shape roughly the size of hole spacing and try feed it in one hole and out another.