First: Thanks for taking the effort to maintain all of these legacy plug-ins for Forge, it's really what Modded Minecraft needed. A million different mods just to fix a handful of Vanilla Bugs? Who thought that was a good idea?

Since you seem eager to combine more mods in your project, I'd like to make a few suggestions:

Parries particles fired from entites back to them when blocked by a shield
https://www.curseforge.com/minecraft/mc-mods/parry (LGPL)

Fixes the stupidly broken vanilla Nether portal behavior
https://www.curseforge.com/minecraft/mc-mods/netherportalfix (Permissive License)

Pairs great with the already installed FastWorkbench (Although LoliASM/CensoredASM seems to do that already?)
https://www.curseforge.com/minecraft/mc-mods/fastfurnace (MIT, pairs great with already included FastWorkbench)

Allows people to change their audio configurations on the fly, very handy
https://www.curseforge.com/minecraft/mc-mods/more-sound-config (GPL)

Allows for easier port-forwarding when hosting a server on a client machine
https://www.curseforge.com/minecraft/mc-mods/lan-upnp (LGPL)

There is also this mod that causes non-fatal errors when pinging too frequently, not sure if you'd be interested in fixing that and merging it into your project, but I'll let you know about it anyways:
https://www.curseforge.com/minecraft/mc-mods/chat-ping (MIT)

Hope I was able to give some inspiration.

I really hate to be that greedy bastard that keeps on asking for new features and chucks requests at a project's author like they got nothing better to do, however I got some more suggestions for you to put on the pile of requested mods to merge, plus I found an incompatibility.

Incompatibility with FPS Reducer
https://beta.curseforge.com/minecraft/mc-mods/fps-reducer
Now, this is going to be a little bit of a pain simply because the mod appears to be licensed All Rights Reserved and no source code is available. It seems that the "Smooth Scrolling" tweak cause the menus to jump around when the game is off focus and FPS Reducer gets active. I've had a look at the mod decompiled with the FernFlower decompiler and it doesn't appear to be doing a whole lot, for a matter of fact, I believe most of the code has to do with displaying the FPS in the corner. Maybe that's some functionality to integrate in Universal Tweaks, too?

Fullscreen Windowed (MIT)
https://github.com/hancin/Fullscreen-Windowed-Minecraft
Hasn't seen an update ever since 2017.

Stackie (MIT)
https://beta.curseforge.com/minecraft/mc-mods/stackie
Same here, last update seems to have been in 2017.

Time to live (MIT)
https://beta.curseforge.com/minecraft/mc-mods/time-to-live
Forge version development abandoned since nine months, although 1.12.2 has been for longer.

InstantUnify (MIT)
https://beta.curseforge.com/minecraft/mc-mods/instantunify
Last update was 2019, unifies drops from different mods with same OreDict names (e.g. copper ore)

Extended Days (MIT)
https://www.curseforge.com/minecraft/mc-mods/extended-days
Last update was 2018, hasn't really been touched ever since. Seems like it's likely to break other mods, might be worth checking out yourself.

Thanks alot.