This is enticing, but seems kind of impossible to do in Normal+ difficulties without some cheese tactics or additional modding. The lack of coal is a surprisingly brutal touch.

You need steel to build doors that can withstand the pressure difference -> you need a greenhouse to make charcoal (inside) -> you need to trade for water to make a greenhouse (outside) -> you need steel for the airlock.

Definitely underlines how hostile Venus is in real life ;)

A custom start that adds a couple of blast door kits would make this feel maybe feasible.. waiting around for the airlock to cycle would be awful, though. Humans can tolerate some pretty insane pressures with special breathing gasses (5-6 MPa w/ heliox), but it would feel pretty cheesy to mod up the tolerable pressure like that without also adding mechanics for all the risks associated with it (oxygen toxicity, bends, etc.)...

When I get the time to do some modding, I might do some twiddling with it and see if I like it.