I have a bunch of requests that I'm certain likely have all been asked before, and all would be fairly large projects so I wouldn't expect them to be added soon. They are all features from other Doom source ports that I think would be very useful for SRB2 modders to have available. The reason I'm asking for them is because I have a big Sonic fan game project that I'm planning that would require a lot of features, and the engine that I have most experience with is the Doom engine; I'm currently debating whether to use GZDoom or SRB2 as my engine of choice. It would be entirely 2D platforming. I have half functioning engines working for both, but I would like to end up using SRB2 to help support a fellow Sonic fan game, and one I've grown up with since the early 2000's. If I can get what I need out of SRB2 and not GZDoom (Which has a few severe flaws that are putting me off that SRB2 doesn't have) then I will use it for sure.
Anyway, the requests. I don't know as much about SRB2 modding so some of this may already exist, but here goes...
.pk3 files: A much easier way of storing and working with data then all lumped into one giant list. I feel like this is something SRB2 might already have but i haven't seen documentation on it, and couldn't find any on the wiki. The project I have in mind will be enormous if my current plan sees fruition and require a boatload of new resources, likeyl even a custom .exe eventually. pk3's are becoming more common throughout Doom source ports due to easily organizing all the data into separate folders and subfolders, making changes relatively easy and pain-free.
True-color renderer for software mode: Not a necessity, and a huge pain to get working, so I wouldn't expect this one. There wouldn't be a need for a COLORMAP anymore if this was implemented, and the palette restriction would be lifted too.
Ditching flats: ZDoom and Eternity, among other source ports I can't think of, can put patches and textures on the floors in addition to walls, making flats obsolete as a file type to use. SRB2 is leaning farther and farther away from the original Doom code, and already supports different sizes of flats than just 64x64. There isn't really any reason to keep flats around as being separate from textures.
Upgrade to UDMF map format: What can I say? The UDMF map format is simply superior. The ability to rotate any texture alone, whether on floors/ceilings or on walls, is extremely useful. I imagine this would be a hell of an undertaking though and require a very updated or entirely new map editor to go with it though so I'd understand if this took a long time to implement if it ever was. Not to mention that all the mappers would have to get used to how much more complex it is, but once they did it would be much more flexible.
Of these all the .pk3 thing is the one that I and many others would benefit the most from. If these have already been discussed I would like to at least read over the reasons they may have been rejected or shelved.