I don't personally... I was just assuming Goku and Vegeta would get the same boost as post-RoSaT Gotenks and Boo arc Gogeta.. I really don't know what to make of fusion and pre-RoSaT Gotenks..
For your second point, I personally don't think suppression affects the outcome since I go with Metamoran Gokhan > Gotenks-Boo > Gogeta.
If Goten & Trunks didnt got more than 2-3x stronger in Rosat and Gotenks got much much stronger than Before entering Rosat, CG SSJ Gogeta is Super Boo tier imo , with Base being more than enough to roflstomp Gohan
My idea is that SSj Gogeta (Boo Arc) is equal to SSj2 or SSj3 Gotenks (Post-RoSaT), which puts a hypothetical SSj Gogeta (CG) above Fat Boo at the minimum.
Yeah, Gogeta flat out stomps the heck out of his son.