Mela
I want to add my experience. I went through a very similar process about 18 months ago. I was an otherwise quite healthy 52 year old, active, non-smoker whole life and social drinker when I got my stage 4 SCC diagnosis (right side of tongue). I chose radiation as my oncologist told me the chances of recurring (for me, every one is different, as you already noted) went from about 40% to about 20% if I did 60 Gy of IMRT treatment to mouth and neck areas.
The side effects so far have been as expected/discussed with my medical team - lots of dental work (root canals, crowns, fillings), dry mouth (significantly improved but still there), loss of flavors (most are back now except nothing spicy and no alcohol), some tightness in jaw and neck muscles and tongue. I have reset my expectations to always have some sort of dental work in my future. But, for me, reducing my odds in half was worth it then and I still feel that way (but it has only been a short period).
Trust your gut and good on you for reaching out to this space. I did not find OCF until after my radiation treatment. Tons of great info, helpful people, and support here. Happy to answer any other questions you may have as I went through similar surgery too.
Wishing you the best.
Nels