Yes I would color grade the Osmo. Very easy in Da Vinci (which I use thanks to you :))
The slo mo is easiest with Osmo, but I like the Hero sharpness. I want to get the Hero 9 with the lens mod. Have you seen that. You can tilt it, even upside down and the horizon stay flat and level !!! Its crazy. Extra $100 tho. There is always more to buy lol.