To answer all questions regarding updating mxl to D2R
1. Lack of TCP/IP / Server Emulation
Let me get straight, medianxl have become to current form thanks to the community for players who kept playing on multiplayers for years. Without this 2, you pretty much stuck with SP only gameplay, which probably similar how original median was designed back in 2007
2. Lack of code-edit
The game engine changed alot with d2r, since it added 3D graphic on top 2D engine. The sigma is long hard work by whist & the team to reverse engineer original d2 code to implement quality of life changes, perfect for median xl experience. Without this, you are stuck with soft-mod, aka editting via tons of tables
3. Extra graphic asset
Aside from soft-mod, even the original median have tons of asset added to the game. Some I think are probaly easy like skill icon or gear sprite, but the concern are heavily revolved around 3D asset. We dunno how modular those are, but definitely not easy to add asset for both 2d and 3d layers. This include monster sprite, spell effect, sound effect etc.
4. Map editor
This another thing to consider since the tile set in median is junbled up from various act, Im not sure how it will work in d2r. In fact I dunno if current mxl even did add any tile set asset to the game.
5. More DRM
Last killing blow is d2r now DRM heavy. Let just say it, not everyone bought legit d2 here. The game copy required you to login to your battlenet account even for single player. I think the only multiplayer you can probably play with are on open battlenet, but even that I dunno how they gonna manage various mods installed in each individual copy.
