Would you please elaborate on why you'd choose the Ohana for low-G tuning and the Kala for high? I'll want to add a tenor low G at some point and am curious. Thx!
The issue with low G tuning is to try to avoid the boomy sound of a rogue note when the body resonates at that frequency and overpowers the other strings sounding terrible. Some people swear by various wound low G strings (Fremont Soloist being a common favourite) to avoid this issue but I’m not one of them often finding them more boomy than the usual unwound strings such as Worths.
The other solution is to use an instrument with a body which does not tend to resonate at that frequency, either smaller or bigger, and this is where Ohana tenors differ from Kala. In my experience Kala tenors (I have owned one) have a body size which sits squarely at the low G frequency and boom, whereas Ohana tenors (I have owned two) have a noticeably smaller body volume and do not. I much prefer them for low G.
For traditional re-entrant C6 tuning I prefer the Kala size as they tend to have more volume and for re-entrant Bb6 I have no preference.
I have never played a Pono so cannot comment but I have seen threads on here which claim that certain models can be boomy. But that is all second hand info whereas the observations above are my personal experiences.
IMO. FWIW. HTH