As a person who has watched prtty much every arrowverse show and has seen most characters evolve, I must say out of the big bunch Allegra has one of the biggest problems with her arc/story in general.
Most of the biggest problems are thanks to Wallace, as seen in Chester too and a tad bit on Cecile in my opinon.
All her arcs are made or to basic or VERY boring.
She's used as an extra. If this continues I'd rather have her as a reccuring character.
She has had the same arc of Nash & Esperanza for 2 fucking seasons.
Tbh she dosen't really fit in the "Flash" properly, maybe her own show with some character changes..
Ways to improve her character:
Give her a voice, and a fresh new storyline with her powers as seen in rayo de luz, we know she's op.
Put her on the field more, not behind the computer!
Continue her story with Chester but not make it all of her arc.
Get her a superheroe suit and make her not only power the machine lol
If this is done I want more:
Power scenes! The cgi for them where amazing
Maybe her own show but with this changes and more to make her actually intresting, and enjoyable to watch
I have many problems with the flash like I'd rather have a hole speedster team tbh, but ik that won't happen so us as fans should cassualy give feedback on ass characters like Allegra.