I think which tanks work and which don't as far as dimensions is more about personality than fin type. I have never noticed any of my HM and OHM Betta having problems in a taller-than-long
* tank? My Plakat is in a 20 long and not nearly as active as Dexter, the OHM/non-biter, who was in there before him. Dexter went to the tall tank and his activity level didn't slow down. Tried Clooney the Plakat in the same tank and activity level also remained the same. But that's just my observation.
And I'm the opposite: To me, Plakats do not look like Betta. I only have Clooney because the Neons nip the fins of any HM or OHM I've put with them. As Neons are Gary's favorite I'll always have them and, thus, a Plakat.