I have a schizophrenic opinion about situations like yours. I’m not a fan of doing nothing, so the one doctor that suggested that, my personal opinion is you should stop listening to them about anything. That is not a plan.
On the other hand I’m not in favor of over treating things either, which some doctors and hospitals are prone to do. You can blame that on an over abundance of caution, and unfortunately sometimes financial incentive.
So here is what we actually know about dysplasia. Of low and mixed low-mid grade dysplasia, only 25% of the time does it move to malignancy. High grade pretty much always does, and needs to be removed or radiated. The problem as you have stated is this is not something you can see or feel, so knowing if it is low grade or high is always dependent on a biopsy. In practical terms are you willing to get an incisional or punch biopsy a couple times a year? That time period would ensure that if it was moving to the dark side, you would catch it early enough to deal with it through a minor procedure. The fly in this ointment is that we know that people, more women than men, that have this occur with no known risk factors, very often have multiple sequential recurring cancers every couple years. At some point if that is you, you have to say when have you had enough little bits of your tongue dealt with in a non replaceable surgical manner? The guess is that these people have a genetic aberration, or stated differently an inherited genetic frailty that allows this all to happen repeatedly.
Having radiation will ultimately deal with this. But radiation treatments for something that is still small like this come with lifelong side effects. Some very unpleasant as I can attest to. So if that is part of your treatment plan, I would want the smallest practical field of radiation, and if possible to get less invasive proton beam radiation. The push back you will get on that will be that it’s more expensive and your insurance may balk.
So that’s a lot of writing to give you nothing actually actionable. I wish I could offer better advice, but at least this gives you a framework to think of your choices within. Good luck with this. Please post back in this thread what you decide to do and stay in touch. B