On-off topic, I remember toying around with team spawns a little on v6a MM7SHA so that teams don't "spawn with a crosshair over a player" and while that's true, I stopped that, there really doesn't have to be much effort placed on either team to recreate that same effect.
Worth possibly looking into rotating Wily around the side of the building, that way they start in about the same spot but avoid immediate sightlines on spawn easier.
(https://i.gyazo.com/3ecd65d1f0c009bbc4b9d5ca342b9789.png)
MMBKIN remains untouched as of v6b, so I'm going to put down in writing that the team spawns here are pretty one-sided towards Wily.
(https://i.gyazo.com/17c12d4c9565041638df4738582df08a.png)
Light's only reliable path forward is down into the lowest elevation area onto the entire map, which they are unable to escape from without passing by at least some of Wily team by taking the stairs near Ice Wall. Their access to mid is either through the sightline-blocked drop down near Proto Buster, or down the hall and through the narrow door on the north side. If they want any sort of high ground, they must go north through mid/low ground, jump up a staircase to reach Flame Blast, then go through another chokepoint (either the one they are likely being shot from through, or the one closer to Remote Mine). Since the map is small, it is likely an aggressive Wily player will already be there and ready to punish their approach.
Wily spawns on the highest point on the map, and can easily reach as far forward as Pharaoh Shot and Remote Mine in the time it takes Light Team to gain any ground. Map control becomes effortless for Wily because they already have access to the largest sightlines on the map.
(https://i.gyazo.com/7dcd006867546fc67f2af4fe0e94af22.png)
This is a proposed solution that would rotate both teams around the center, putting Light closer to Flame Blast and Wily closer to Dust Crusher. This is a slight nerf to Wily and a big buff to Light, but should put them in relatively better playing fields. Wily now has to jump up to reach and claim their previous highest point (but still have access to all the perks that area comes with!), but Light has more immediate access to both the higher and lower layers of mid as well as a safer room to play from in the Remote Mine area. If Light puts up an amazing offensive front however, Wily will have way more room to duck and leave than Light does currently, as they can safely move through not only the lowest channel but through lower mid as well.
Cossack and King spawns are sort of an afterthought here. Adjust as needed.
And since MM7SHA also remains untouched, I've gone ahead and added a visual to that post as well detailing what I'd do for a v6c edit.
I'll keep this brief to reduce the amount of salt and vitriol I can possibly put in this post (and reduce the number of times I have to edit my own wording), but the Light Team spawns on MM3TOP could be better.
(https://i.gyazo.com/96545333075092567e67fa754cecb4c5.png)
The room you spawn in is one of the most dangerous, easily exploitable rooms on the entire map, with a (campable) ladder being your only way out that leads to high ground, with your only way out to low ground being this thin hallway towards the staircase setpiece with Water Wave. Wily Spawn's high ground has multiple clear vantage points over this area, and as you can see from the diagram above, Cossack Spawns here. Holding this room is nigh-impossible, and your routes out are treacherous, so players are forced to leave basically immediately.
In addition, vanilla players are starved of resources from this spawn. They have immediate access to Shadow Blade, but Wily is not too far from retrieving it either. Wily, however, gets Spark Shock, Water Wave, Drill Bomb, and Bass Buster all just within their warehouse. Since the spawns line the entire warehouse, the entire enemy team is likely to have a diverse set of ranged options to deal with people fleeing from Light spawn, even if Light members are heading towards desirable weapons like Top Spin in the middle or their own Drill Bomb near the northwest building. Light may be able to make it to these high and central areas faster, but these areas are extremely open and their paths to reach them are significantly less safe than Wily's paths.
I believe this is a bandaid solution with no true resolution to the problem (I do not believe this map with its current layout is capable of having "balanced" team spawns) but here's my best shot at making Light team less completely miserable.
(https://i.gyazo.com/448759d4f3ed5fd4b694c0d4a6cf2e50.png)
This gives Light a multitude of options for where to go, and gives them a spot to actually hold for some time since it overlooks mid. I still consider it somewhat treacherous and exploitable, since this high ground is a straight line and most of their surroundings is pit, but it is undeniably stronger high ground from mid's perspective than Wily's is.
This is my least favorite map in the game, so I'm open to some pushback or some "with a grain of salt" thinking, but I do believe I have some observable and actionable critiques here.