Maybe this is more inconsistent behaviour rather than a bug, but it seems to be possible to upgrade biter spawners (I did it with a ghost cursor).
It's not possible using a upgrade planner as mentioned in https://forums.factorio.com/viewtopic.php?p=655170&hilit=biter+spawner+upgrade#p655170
04-18 ...

I for one HATE the fact that the blueprints in "my blueprints" and the inventory are linked now.
When I delete a blueprint from my inventory it also deletes it from "my blueprints".
My way of keeping my inventory clean with blueprints was to only ever use a couple, and then clear them with shift ...

Why are ''My blueprints" and the blueprints in my inventory linked? When I delete a blueprint from my inventory it deletes that one from "My blueprints". Is that intended? The blueprint library was good before, whyyyy

That's it! I want it back!

In all seriousness though, i get that the developers don't want it enabled for new players, but at least give me the option to enable it.

We need tunnels because of throughput issues, we could have different recipies for different tunnel lengths and expensive research or something as this issue of thoughput will only arise in the late/end game. I currently have 130+ trains and I need something like this https://i.imgur.com/K8lpkEur ...

I was wondering how much oil my factory was consuming, but I didn't see anything in the production screen.
It would be great if the consumption and production of fluids was shown in the production tab