I've done month on and month off and 6 weeks on 3 weeks off traveling to Thailand during off time since the end of 2010.
In this time I've been stopped twice at immigration and asked questions but never been denied entry. Since the last time I got stopped I've been a bit more worried about it and I'm working on a more permanent option.
I was also here on visa exempt entries and extensions for roughly
***
months in early 2016 as I lost my job.
You'll be absolutey fine short term to mid term, if you plan on being here and doing that for a long time then look into other options for visas to be safe.