I agree Hex about the new forge options greatly increasing the aesthetic's of the maps and piece options, but this would be more about getting the best quality / scaling into the playlist to best represent the forge community. The people who created existing remakes have a passion for them and I bet if contacted would gladly go back and update their maps to have them considered. I can message them on here and Xbox Live to let them know that there would be a contest for matchmaking consideration and updates would be required for their maps.
The biggest one for me is scaling. We need settings and map scale that work together perfectly. I would be extremely passionate about getting a Forge community collaboration together to work on remakes and even new maps that support classic Halo game play. We need to agree on settings though if the maps are to all work consistently. Old School isn't appropriate as it was made to work on maps people had scaled for H5. Maybe slowed down movement speed and acceleration could work though. The starting weapon is another debate. The H2 BR has way too much magnetism and although I can enjoy it in casual customs, I think it would get boring fast if used for long. The H5 BR is more skillful but perhaps ruins the classic vibe. The standard magnum is most competitive but doesn't have the strength of the BR making power weapons stronger than desired. With classic Halo you want more weapons on map than you usually allow in H5. Evolved is cool but I think the kill time is a little fast for people who want the game to play more like H2/3. I think standard AR and Magnum starts is probably the best all-rounder but with increased health so that autos are weaker and power weapons are also less powerful as they would need to be without spartan abilities. I'd be up for experimenting with settings at some point later in the summer and see what you guys think. If we can agree on them that then means we have a solid reference for each map to be scaled around.
Out of all the testing we've done personally I've always been in favor of Classic BR and Gunfighter starts. Though it doesn't feel as good as the H2 BR it still does to a certain extent, so I'll give credit to the H5 BR where its due. Combined with the classic scope and less magnetism it gives off a good feeling when you get those multi-kills (Or hell, just kills in general). When it comes to secondaries both magnums work for me. With the Gunfighter, it allows for fast swaps and clean ups when your BR runs low, but I will admit it feels a bit cheap when you win the BR duel due to the Gunfighter's fast clean up succession. With the standard magnum you have no speed buffs, but you get the Smart Scope and one less bullet to put someone down (Also feels more rewarding when you clean someone up with it in a BR duel). Really it goes both ways, keep momentum fast but have a bit of a cheap fall back, or have a rewarding clean up weapon that's even possible to use as a primary if you're good enough -- but still slows gunfights down a bit. On the subject of AR Magnum starts, I feel like it seems too Halo-Fivey. Swapping to a somewhat H2/H3 loadout would instantly give the player a feeling of "Oh, this isn't H5 standard settings, this is fairly different, yet familiar...". The CBR + magnum loadout, to me, feels like a classic experience, but made for H5. Like, it gives off a good feeling and I can't say exactly why. In terms of movement, yeah, just tune it down a bit for classic scaling as you said. Being that its for H3, grenade count would probably have to go back to 2 max. But yeah, that's pretty much my view on the whole thing, more tests on all ideas would for sure allow us to get a better feel and have an objective agreement.
So right now I say we wait for E3. If there really isn't an H3A then first off, WTF!? but I think we should only bother with this if we don't get H3A. If Microsoft/343 continue to prove they fail at supporting Halo, then I guess the task lies with us. Test settings, agree on them and get a playlist of scale remakes and classic game modes going that can hopefully gain traction in the community and push 343 to introduce some kind of H3 themed classic playlist. Even if it doesn't get to matchmaking it would at least be a solid playlist to use for custom lobbies.
I did forge H3 Assembly and finally uploaded it to Forgehub. I know it wasn't the most favorite map, but I hadn't seen anyone else attempt it. I do want to say thanks to @Overdoziz for mentioning very long time ago that it was too shiny. I turned it all down and applied the covenant theme and it looks a lot better now.
I'm not a fan of that particular purple shade... try switching it up some by using a few different purples, and I think it will look EVEN better. Perhaps some pieces could be shinier than others, as a way of accenting?