Twitchy means "not as predictable" so to speak, sometimes it gets kind of a "tick", and it might flap in some conditions when really windy and turned hard and maybe depowered, and the full kite does not feel as good/rigid.
But I dont think many has made 5 strut kites in the windy wavekites meaning 4-5-6 m2 sizes nor earlier, where it has been 3 struts mostly.
In the 7 to 9 m2 yes, several has chosen 3 struts now you are right, as it seems to fit most kitesurfers better as more versatile and lighter, which is better for many things, but will suffer slightly in terms of twitchiness yes.
So more difficult to find a 5 strut nowadays indeed Mikelet.
But they are out there, also the new Takoon Furias are 5 strut even the smallest 6 m2 .