Thanks so much for the feedback, was super fun seeing somebody else playthrough it also :D.
I did start noticing how hard I also had to focus on the PSI meter while descending but I didn't have time to fix it so I just had to commit to that, afterwards I was thinking that maybe the PSI should have been a bigger element of the main screen so it's always visible perhaps some part of the drill.
And as you also figured out the fuel didn't end up doing much, it was initially added to prevent the gameplay of venting the PSI as soon as possible all the time. But I didn't really think the upgrades through that much for the fuel so it quickly disappeared as a mechanic. If I had some more time I would probably have tuned it more.