Thank you, Duplode! You've done a lot of testing. You found some undocumented keys and bugs I hadn't noticed!
I compiled the Windows version for 64bit (I actually had my brother do it for me, since I use Linux), but I could compile it 32bit if necessary. The Linux version is 32bit because I'm currently using a 32bit Linux, but would like to upgrade and probably next versions will be 64bit.
What Linux distro are you using? Were you able to run the binaries without any dependencies expect for the 32bit lib? I'm interested in knowing more about this. The error about file name duplication, I had not noticed, because I did most of my tests under GNU/Linux, but now that I read it, I know exactly why it happens. I will have it fixed and upload the update. It's not hard to resolve. The editor can actually combine track elements already, but I compiled it without that option, because I hadn't added the switch yet and I preferred the default to be more like the original editor. Next version will include at least a key shortcut to switch editing mode. There is also an option for not showing the terrain warnings. It can be used for checking what's "under the yellow box". I'll also include that in the next upload.
About the high CPU usage, I've noticed that in some of my programs and I really don't know why that happens. I think I need to include more idling time in it. I can see DOSBox takes some time to load the DOS version. I believe it is because I load the Targa graphics byte by byte, as the screen format is different from that of the graphics. I could make this work faster by changing the file format, but the file would be 25% larger and the loading time would only vary significantly under DOSBox. I'll consider it