Really, what I'd like to see most out of MQ in future releases is more variety in terms of quests and non-rare equipment. I've been playing MQ almost since it first came out (and have played every AE game they come out with) and I feel like MQ has lost some of what made it interesting in the beginning, namely finding the best combination of mechas and equips for any particular strategy. Nowadays, this is difficult to do, since equips don't stay available for long, and SCMM often come preloaded with weapons that are either OP or already so cohesive that customization actually proves detrimental. I feel like what makes DF, for example, so successful imho is that the equipment system focuses heavily on setting up elemental advantages while buffing your own stats. Each battle requires the player to make decisions that noticeably impact the outcome of the fight. MQ focuses on special effects, which isn't a bad thing, but the enemy design makes it so that most battles can be won simply by brute power (and it is often the best strategy, since faster kills = faster exp/creds) with no real thought towards strategy beyond the basic 'use equip A before equip B'
On the debate of the SCMM, I don't really have a problem with them. However, it seems pretty clear that developing the SCMM is taking up a significant chunk of time, which is detracting from the quality of general releases. If decreasing the frequency of SCMM (which by now feel more like just a novelty rather than anything unique, due to the number of them and, imo, stagnating designs) is what it takes to improve the overall quality of MQ releases, then by all means, do it.
Some ideas for future releases:
-NSC mechas with only a specialized body attack (something along the lines of the zargon design)
-update Tek's Mechs with new equipment and art designed around said NSC mecha
-possibly offer set-type bonuses for using cohesive equipment, or using weapons designed for specific mecha (similar to how some weapons can only be used with certain mecha)
-enemies with resistances/weaknesses to various special effects
-more diverse mecha designs: ex. a small low hp body with higher evade/acc and fewer equip slots, a mecha with high damage and energy consumption
-while an 'equipment weight' system probably isn't possible with the current setup, an interesting idea building on the above suggestion could be having quests that limit the number of items you can have equipped at a time, or limiting the types of mecha that can be used
-weapons already have 'elements' of a sort (ballistic, explosive, etc): make these actually matter (maybe explosive weapons have wider damage ranges, ballistic have stabler damage, or integrate damage weaknesses/resistances into more enemies)
-Since this is a mecha game, it makes sense that you have to stick with a single loadout for any quest, without being able to swap out mid-fight; it would be interesting to see quests that actually make you plan your loadout ahead of time, instead of being able to just go in guns blazing; maybe a quest is known to be long, so you'll need damage reducing specials, or maybe it's a boss fight so you want to maximize DoT, or enemies have certain defenses that require specific counters
-Mods that do something besides buff stats, similar to trinkets in DF; this can either be a persistent special-type buff (+ armor, + debuff resistance, + chance to do...something, etc), or provide some sort of auto-trigger single use effect (ex. repair kit that adds x% hp when your hp <25%, temporary armor boost when hit by a crit, call in air support after 6 turns of battle for a bonus attack)
Several of these ideas build off of code that already exists in-game: element resistances, for example were showcased in that one Gears class that came out a while back, before disappearing, never to be seen again. I think if they reduced the number of mecha releases and focused more on the quests and building up the game engine, MQ could become a much better game.