Looking at the bottom 20% of frames by cumulative usage, most of which I play often, a few stand out to me as potentially benefiting from a rework. Might have some bad takes, so feel free to tell me how you play them! Always happy to learn something new about frames I haven't clicked with.
Need a refresh
Atlas: very tied to weapon selection which makes SP Circuit dicy. I'd like to see more innate power on his kit, or a change to petrifaction that improves its damage buffing, maybe with armour removal.
Equinox: augment syndrome. Some of them could be passives or otherwise extended (e.g. Energy Transfer could work on Pacify & Provoke too). Major systems rework could let her mod Day and Night separately, which would be nice as they both like different stats.
Chroma: funny damage man. Got a good buff with Circuit scaling his Spectral Scream (but not Effigy! what!) into actual strong damage abilities. The "keep two buffs rolling" playstyle is bad though. Spectral Scream could be a one-handed single cast that shoots actually good projectiles. Would also be nice to have Vex Armour store its buffs for recast, for accessibility reasons. Let Elemental Ward be recastable. Otherwise give him an augment or a passive that lets Ward and Armour refresh on some condition. Why does Gyre get to have all the braindead pew pew fun?
Could benefit, arguably fine
Gara: due to how full and synergistic her kit is, hard to fit shield gating on her build without Decaying Key usage. Good at health tanking, but that has scaling limits. Mass Vitrify deserves a buff to bring it in line with how easy Snow Globe is to scale infinitely.
Oberon: his damage buffing is very conditional on enemies reaching his garden. Very harsh range (235%!) and strength requirements if you want a fullstrip build without giving yourself RSI by double-casting Hallowed Ground constantly. Reckoning being able to blind on kills within a duration would be nice. Renewal could benefit from shield generation due to how healtanking falls off.
Lavos: please give him scaling survivability without dipping into Muzzle Flash or Resonator, or Arcane Trickery.
Trinity: absolutely horrible to play with the agonisingly short buff durations; this one is definitely personal preference though. Might benefit from damage buffing such as EV applying a small damage vulnerability in its area, or Abating Link being a target-radial armour strip that can be recast.
Out of the other low-usage frames, who would you like see refreshed or reworked?
Good points about Oberon. I just feel kind of bad about Renewal being my helminth slot for long runs; I ditch it for Condemn. And yeah it's hard to know what to tweak. Smite is very underrated, especially on Nourish builds and in Circuit.
Yeah, Equinox feels like a prototype frame who either borrowed from her contemporaries in a weakened or more conditional form, or else gave her abilities to later frames in a buffed form. On the other hand it does mean she has an extremely versatile kit. Red Mage energy.
Since there is the Phoenix Renewal for the health side of things, maybe Renewal could get another augment that adds some kind of shield replenishment to the ability. I feel like DE would probably make it slightly too conditional to be super realistic in actual gameplay, (like every enemy killed on Hallowed Ground restores X shields while Renewal is active) but I've always thought augments should lean more into slightly changing the way an ability works rather than just providing a buff. When it provides a buff, it ends up feeling mandatory in builds, and it can get annoying that it wasn't just baked into the ability to begin with