A couple of questions/comments. You can see if it might be worth while to add to an upcoming revision.
Most, but not all, of the Doom2 textures have their images centered on the texture. In x alignment or Y alignment.
A few that do not for example: sp_dude1, sp_dude7, sp_dude8, stucc02, sw1cmt, and a few others. Still others are off of Y alignment.
I think it might be helpful to have an idea where to start when trying to align these. I can certainly do it by viewing the x-align when I am viewing the graphic. But if you could add a grid/scale/ruler or whatever to the graphic viewer it would save a little more time.
The graphic viewer I am talking about during x-alignment is:
8. show texture, or 9. show multi texture, align.
The auto x align works perfectly but assumes you just want to align the edges, which is all I want about 98% of the time, but on occasion I want to use some of these other textures. And have thus far just used trial and error until I get the image centered on some of the odd ball line lengths or room heights I have. Don't get me wrong, you have the best viewer out there, and it has saved me a lot of time and many game bootups to view the graphic, but this might save even more time.
I don't seem to be precise enough with the mouse to just drag it, I always seem to move it up or down a little when dragging and then have to go back and fix the y alignment. That is not hard to fix, only takes a few of seconds as you know. None of this is all that hard to repair, but wondered if you might think about the possible addition of a grid or whatever. It would also help during Y alignment, during those times when doing it by hand is the only way to get it right. You might be able to bring up your resident map grid at the same time as the graphic viewer, to overlay the graphic on the grid.
That new arc tool is great, nearly perfect circles in just a couple of clicks. It is sweeeet!
Thanks for your consideration,