Well, considering the fact I've seen other people modify sprites and such before for Freedoom that were other peoples submissions, and that all the assets in the Freedoom project are allowed to be edited or released, (at least I'm pretty sure that's the case) I did think that it was alright for me to try to refine it on my own. I suppose it would've been better to discuss this before acting. My apologies.
Anyways, since nobody else has said anything on your map, I'll list off my issues with it:
First off, there are a few dead end areas such sectors 617, 63/84, and many other rooms which are dedicated just to one weapon such as sector 9, 27, 92/95, and 126/515. I feel that the weapons should be placed in the map that flow better with the design rather than you having to step off for a moment into an empty room to pick it up.
Second, the maps design is either flawed or meant to have a huge portion of it optional. You can easily skip a good two thirds of the map by just going in the door on the upper east side of the river, since all of the keys and such to move on are in there. I'd suggest making it so the player has to explore at least part of the mining facility.
Third, there is an abundance of long, narrow hallways with only an enemy or two (or none) in them to compensate. The biggest ones I can point out would be sectors 25, 122, 171/419, and 188. I'd suggest widening them and making there be more interesting battles or something.
And a minor fourth thing, there's an extra yellow key, specifically thing 186, which seems to be added because there's a deathmatch spawn in that room. I'd just suggest just making that side of the door able to open without a yellow key.
There's probably other things I could point out but these are the most major problems I currently have. Again, I apologize for not coming to you first about these issues though. My mistake.