You can simply present your current employment contract and also ask your employer to sign a letter confirming that you’re allowed to work remotely.
In my case, I was approved for the DTV using a four-year-old contract along with a letter from my employer stating that I work remotely and that I won’t take jobs from Thai companies. Prior to that, I was on visa exemptions and ED visas.
I also had no problem using my Thai bank account to show proof of funds. In my experience, being straightforward and honest really does go a long way.