As the guide says, the speedrunning differences between launch and rev 1 are the time together 4 skip and faster cutscene skipping.

Well, are there any in-game improvements between the versions, such as graphics, performance, sound, or content? I didn't notice any while playing them, but there have to be major differences, considering rev 1 is 2.29GB while launch is 1.97GB.

But why exactly the bottom-left corner? (image https://ibb.co/rp5v1s7 )

It was like 3 days i sugested an new categorie, "Reach Axiom", wich is BnL Tune-UP - Stowaway to Space. It can be much usefull for training and get stressed XD A lot of games have those misc. categories, so its my opinion