I'm no longer actively working on Loap. At some point I'll probably make a small fix for the music looping bug that showed up in newer versions, but aside from that there's no plans for further work simply due to the low interest in it. With that being said, it's open source (MIT licence), so anyone is free to take over if they wish.
Loap doesn't intend to be a 1:1 accurate replication of the DOS game. This becomes more noticable with custom levels, where some of my custom ones actually needed modifications to ensure they worked properly under Loap. You're likely correct that there's a one-frame (or so) window where the climber is considered to be inside the block above him, but Loap handles this differently (either by not having such a window at all, or by having a different timing of when the bomber takes effect so that it can't do so within that window).
You can definitely increase the resolution of the skybox... if you have a higher resolution version of those images to use there. (Maybe a rip from the Playstation version? I believe it has higher-res skyboxes compared to DOS, which is where these were ripped from.) No special steps needed, just replace the existing image with the higher-res one and it should just work.
Loap doesn't intend to be a 1:1 accurate replication of the DOS game. This becomes more noticable with custom levels, where some of my custom ones actually needed modifications to ensure they worked properly under Loap. You're likely correct that there's a one-frame (or so) window where the climber is considered to be inside the block above him, but Loap handles this differently (either by not having such a window at all, or by having a different timing of when the bomber takes effect so that it can't do so within that window).
You can definitely increase the resolution of the skybox... if you have a higher resolution version of those images to use there. (Maybe a rip from the Playstation version? I believe it has higher-res skyboxes compared to DOS, which is where these were ripped from.) No special steps needed, just replace the existing image with the higher-res one and it should just work.