I suppose I should be happy a response was given at all, but if that really is the reason and the subsequent solution you came up with, I don't really know what to tell you.
Do you really not understand to which degree you are shooting yourself in the foot here?
I'm pretty sure every veteran player will agree that this game desperately needs viable content. And I say viable because there are a decent number of things to do, but almost none of them were ever worth doing because FSC is the only activity that consistently rewards your time.
Arcade runs? Maybe if you get lucky with recipes.
Danger Missions? Treasure room at depth 25, hope you don't like radiants.
Dreams and Nightmares? Why even have enemies drop money at all.
The way this "fix" was implemented makes me think you didn't even realize how hard you struck gold with the forge update. The game finally had a level-agnostic way to consistently earn something valuable for your playtime. You could play basically any content in the game and be rewarded proportional to your own skill, due to how having to jeopardize your loadout to fill with 0* gear worked. You could finally enjoy different facets of the game without feeling like you were wasting your time. And now? Now we're back to square 0.
Since there seems to be no intention to making existing content viable with changes that would take literally zero effort (Increasing the depth of danger missions, adjusting stratum 1,3 and 5 rewards for arcade, lowering costs for shadow keys), I am just going to have to assume you, for some reason, want people to exclusively run FSC? At this point I really don't get it.
This is your evidence that GH doesn't actually care, by the by. It took them how long exactly to patch some (but not all) of many longstanding infamous bugs, like Neutralizer's damage values clearly being well below intended values? But there's a minor exploit with their changes to the forge gambleboxes and oh gee they gotta patch that! Happened in two months and that's not accounting for however long it took for them to decide this was a problem.
I cannot imagine that, logistically speaking, this specific abuse of alts was especially problematic. Buying/crafting low star gear and heating it with an endgame character has pretty negligible costs, so getting them for free with a new character hardly saves anything. But, this exploit is a potential threat to their economy, so away it goes.
Will they ever patch un-Punchable shield status UVs? Do anything to adjust the hostile design of Black Kats, or the lukewarm-at-best rewards for the grueling Tortodrone fight? Adjust the game's equipment so that Chaos/Black Kat and Brandish/Magnus/Autogun/Alchemer don't overshadow everything else? Keep in mind that GH didn't even actually fix all the antigua charges, hilariously — last I checked Silversix's charge no longer despawns when you're against a wall, but Blackhawk's and Raptor's still do, unless they've quietly patched that since I reported it almost a month ago. Or how about the Mimic boss fight they introduced years ago, which walls out melee, spawns obstacles for guns, and despawns bombs that are too close; the fight not only restricts your equipment choice by design but also effectively restricts you to the gear that already was good at everything anyway.
GH can say "Spiral Knights is back!" all they want, but the pattern is clear: their interest isn't in fixing the game, but rather in selling us the hope that it will be so we'll keep buying gambleboxes from them. It would've been so easy for them to tune up the notoriously flimsy and janky Tortoguns by any amount, or do anything to improve the player experience of the Black Kat event, or improve the payout of the notoriously underpaying Danger Missions, or improve the drop range of the infamously limited Radiant Fire Crystals. All they've added are new cosmetic rewards, which unlike the existing ones, have the addition of only being available to redeem during the event in attempt to claw in more player retention with FOMO.
So, yeah. GH has clearly shown that they don't care, so neither should you. Making a DLC that frequently went on sale for one dollar free instead and slashing the amount of rads needed by a third without actually addressing the grind are pretty nothing changes in the big picture. Go spend your time and money elsewhere.