As long as you can convince the IO you are a genuine tourist you will be OK. They are clamping down on border bounces, and ppl who use visa-exempt to stay long term in Thailand
I applied in the UK. I'm also self employed but I was advised to setup a Ltd company and make myself a director. I wrote a letter to myself giving me permission to work remotely in Thailand.
Nobody knows how they will apply the rules. They only allow 2 visa-exempt entries per calendar year unless you can convince them you are a genuine tourist. Technically you have only entered once this year and you returned to your home country so I think you will be fine. They are cracking down on the border bounce brigade - the people using visa-exempt entries to stay in Thailand long term.
You can get a re-entry permit while it is under consideration as long as you are back before the under consideration date. The period is usually 30 days but it can be 60 if they're busy. All marriage extension applications are sent to either Chiang Mai or Bangkok for approval, hence the under consideration stamp.
If you have an METV then you can return the day before in runs out and you will be stamped in for another 60 days which you can extend for a further 30 days. Be aware that each new entry requires a new TM30 if you wish to extend. So to sum up, if you time your exit and entries correctly you can get a stay of almost 9 months from a METV.