Can I choose to enter Thailand on a visa exemption if I have a valid re-entry permit?
My situation is complicated. I have an ED visa extension that expires 14 December. I would like to continue study for another year but I will have to do that in a new passport as my current one is almost full. I have already ordered a new passport to pick up in Chiang Mai. I have to leave Thailand next week (before the new passport is ready) and not sure how long I will be away, but probably about 2 months.
If I return end of November and I have a re-entry permit, I'll only be allowed to stay two weeks until my extension expires. My understanding is I could extend for another 7 days but that gives me at most 3 weeks here, which I don't think is enough time to organise the paperwork for a new visa application once I have picked up my new passport.
If I don't have the re-entry permit I would be stamped in for 30 days with the possibility of 30 days extension on top of that, which would be ideal except I'm worried about being denied entry on an exemption because I've "been in Thailand too long". I've been in Thailand over 4 years, with only one entry being a visa exemption (in 2018), the rest has been on non-immigrant visas.
There is a chance I'll be back sooner than the end of November, in which case it would make sense to have the re-entry permit, but most likely I'll need to stay longer than 14 December to organise the new visa.
So my question is, if I have the re-entry permit and arrive before 14 December, can I choose to enter on a visa exemption instead? Am I allowed to cross out the re-entry permit stamp to invalidate it? Or would that invite scrutiny and a higher chance of being denied entry?
I've heard the immigration officers at Chiang Mai are much less likely to refuse visa exemption entry based on having lived in Thailand too long. Does it happen at all in CM or is it only in Bangkok that they have been doing that? If there's more than a 10% chance of it happening I'd rather plan to enter via land crossing instead. I could tell them that I have to enter to pick up my new passport, which is a pretty good reason, but I'm not sure logical argument always works in these situations.
Looking for advice or suggestions about my situation. Thanks!