Honestly, fair.
It made more sense when it was still in the lab and gated progress, but you’re right that it’s kinda wasted now. Perhaps it could become a way to enlarge the player’s bust in addition to their speed and stamina.
Powering up the boobs sounds excellent. Even if it's a mostly cosmetic thing (might need to widen some doors, though, like the offices).
Oh, one other thing I noticed, dunno what you want to do about it though:
Obtaining and using [Redacted 1] will arbitrarily set your max fill, resetting appropriate upgrades from [Redacted 2]. Max Fill ends up resetting to its base value when [Redacted 1] is turned off (does not undo the use of [Key Item]).