What are my options for visa extension in Thailand given my criminal conviction and current DTV status?

Hello.

So im in a bit of a difficult situation. I have been convicted for the business with a nominee, including land. I am on a DTV because before my arrest I never made it to a work permit; the business was quite young.

So in a few months I need to leave for the 6 months dtv run. I have asked immigration if i can travel; they said yes, but they are not sure if I can come back. I have to sell the land, so it's important I come back.

I asked different lawyers and agents what they advise; some say that I can come back without any trouble. I am probably not blacklisted, but the immigration officer at the airport will see a red flag and can refuse entry.

The other offer I've got was via a visa agent to extend my visa i Thailand. I know you can extend your visa in Thailand once per year, so it does not seem to sketchy, but i can't have any fake stamps in my passport thinking it's an official stamp.

Please, do you have any advice or experience through people you might know had the same? Did you hear about this extension service in the country before.

The place where I live, they almost do no extensions for the dtv..

And please, no judgement comments; this case is not black and white unfortunately, but a big part of getting screwed and some naivety from my side.