What are the current rules for obtaining a Multi-Entry Non-B visa at the Thai consulate in Hong Kong for expats with a work permit?

The Hong Kong Thai consulate gave me a new issue today when I tried to renew my multi Non-B visa that I've previously gotten there annually the past 5 years. Apparently, because I have a work permit, they have now decided this means a Non-B can only be issued within Thailand, and they even said in Thailand, I would only qualify for a single entry yearly visa with re-entry permits required every time I leave. Their logic is that having a work permit means that you live in Thailand and do not live in Hong Kong (despite me being a HK passport holder and having address proof in HK and HK ID), so you cannot apply for a Non-B in HK.

They also claimed that all Multi-entry Non-B visas are only given to those without work permits who need to be in and out of Thailand frequently for meetings, and if you have a work permit, it means you cannot get a multi-entry visa since a work permit means you must live in Thailand. I argued they had given me a Multi-entry non-B at the HK consulate 5 years already before, and that my entry stamps do show that I do go in and out of Thailand frequently and do not stay for long periods, since I am just the director of the company (and 49% shareholder) and do not work there on a regular basis. I explained I was required to have a work permit or else I am not allowed to even sign checks or perform other "work" activities, but I don't work there in the traditional sense.

They didn't care and said regulations had changed and Multi-entry Non-Bs are not allowed for anyone with a work permit, and refused to give me the Multi Non-B, finally agreeing to give me a single entry Non-B with 3 month validity. The clerk even went in back for over 10 minutes with all my paperwork to check with supervisors and then all 3 of the counter clerks together explained this same thing to me, so I don't know if rules really have just changed in this way.

The question I have is: my next 2 trips to Thailand are for 5 days in early June, then from mid-August to mid-September. The June trip is likely not enough time to get a year-long Non-B at immigration in Samui since some of the days are on a weekend. My 1st June entry stamp should therefore allow a stay of 3 months. If I get a re-entry stamp during my June trip before exiting, and I return in mid-August, that re-entry still only allows me to stay till end of August per my original entry on that visa. If I apply in mid-August at Samui immigration for a Non-B good for 1 year, will I be allowed to remain in the country till mid-September, per my existing travel plans, or will I still have to leave the country before the original entry stamp's stay expiration at the end of August?