when downgrading with an upgrade planner without a filter, the default tier below express transport belt is bioluminescent fast transport belt, not the normal fast transport belt

Same here.

same here.

Downgrading assembling machine will also give the bioluminescent versions. Kinda annoying.

+1

Either clear next_upgrade or prefix it with bioluminescent- as well.

same here

there's a fork, maybe they can fix this...? https://github.com/nicholasgower/tenebris-prime/issues/5

see also https://mods.factorio.com/mod/tenebris/discussion/675dff94107b553bf8822fa5

well, I hacked some PR, don't know if it would raise other issues, but works for me so far... https://github.com/nicholasgower/tenebris-prime/pull/25

Maybe they https://mods.factorio.com/mod/tenebris-prime merge and we all can try if it works...

Since that has been merged, it feels better for me. There's still something weird going on (I seem to be unable to downgrade red belt ghosts, but placed red belts work...), but it's enough for me now, I don't want to look further into it. Just thought I'd let y'all know.

(Edit: I'm talking of Tenebris Prime, of course https://mods.factorio.com/mod/tenebris-prime)