TOTW v SOTM sets

I have 5 x 88 TOTWs I’m wondering if I cash in on Ovi since they won’t be used in the next SOTM sets? I presume it’ll require 1 x 89 and some 87s? For a possible 92 OVR? I can’t remember how they work!!!

Can anyone remember how they work - and what’s best to do with these 88s going forward?

(Presuming the next event MSPs require 89s too…)