Why it should be moved:
For me, Gleba was the planet I used quality least on and Fulgora the planet I used quality most on (until Volcanus in the late-game).1. Gleba is the planet where quality is the least useful and Fulgora where it is most useful.
On Gleba, since most items (fruits, mash, carbon fiber) recycle into themselves, it is not worth it to try for quality since upcycling is impossible.
While on Fulgora, since you are encouraged to sushi belt everything anyways, adding quality modules to miners and scrap recyclers can produce good quantities of worthwhile rare resources in the mid-game.
Also, Fulgora unlocks many of the personal equipment items which benefit greatly from quality.
On Gleba, the name of the game is maintaining a high throughput of disposable items. This is well served thematically with the stack inserter as it quadruples the throughput of belts.2. Thematically unintuitive.
On Fulgora, you are taking fancy garbage and recycling it into advanced resources - a perfect fit for the quality mechanic.
I imagine that most players will start engaging and experimenting more thoroughly in the quality mechanic on Fulgora once they unlock the recycler and the T3 quality module. This could include making blueprints for upcycling or rolling for higher quality armor and personal equipment. By making epic quality unlocked on Fulgora, it helps ensure that players anticipate epic quality items and eventually legendary quality items in their builds.3. New player experience.
Also, epic and legendary unlocks are basically the only researches that could actively harm production when researched. That happened to me my first playthrough and what I imagine is a risk for similar players who visit Fulgora before Gleba. Since I was only getting at max rare items from scrap and upcycling, I didn't anticipate how the future quality unlocks would affect my builds. So later when I was on Gleba, I accidentally researched epic quality too soon and it bricked some of my Fulgora builds since epic quality items were jamming the belts. This could have been prevented with foresight, something new players will not have and should not be overly punished for lacking.
Why it should stay:
Counterpoint: Gleba is already highly rewarding (stack inserters, spidertrons, biolabs, and T3 efficiency and productivity modules). Also, how much of a reward is epic quality before the recycler or T3 quality modules? Getting epic quality items would be too much of a resource sink. As of now, even with the research, epic quality is still effectively unlocked on Fulgora because only with the recycler and/or T3 quality modules does it become practical to aim for epic items.1. Gleba is the hardest planet. Volcanus has enemies but little production difficulty. Fulgora has production difficulty, but no enemies. Gleba has arguably the hardest of both. Players should be rewarded with higher quality stuff for tackling a more difficult planet before potentially easier ones.
Honestly, no idea how this could or should be solved. Maybe if it's already been unlocked it stays unlocked, but if not it moves to Fulgora science packs? But again, any good solution to that problem wouldn't come from me.2. It would be difficult to update existing saves.
Cheers