My biggest concern is the studies that have been comparing myocarditis induced by the vaccine vs. those with MIS-C from COVID-19 that show that they're not necessarily directly comparable - the vaccine-induced version is also milder.

It is elevated, but the implications of that depend wildly on things like case rates, as events/vaccine doses is static, and events/cases is dynamic. A conclusion reached in Sept., 2021 misses a huge upswing in cases in young men from Omicron, which while milder on a per-case bases has also caused a lot more cases (to use a gaming analogy, making better saving throws, but making a lot of them).

Do you have a source on the vaccine-induced myocarditis being milder? If that's true then it is indeed a crucial thing to keep in mind when interpreting these results.