For elderly arrivals (80+) at Suvarnabhumi, is there a special faster line through immigration or a pay-extra VIP line that could make it happen easier?

Thinking about ways my 80yo mother could visit for a few weeks and the long (16 hour) flight is already tiring enough.

FWIW, she would use a Business Class ticket to make things easier on the plane at least.

Has anybody flown with kuwait airways Are they OK

Has anybody ever been rejected at BKK when using the priority immigration? (Business Class)

I have 7 visa excempt entries in total (2 in 2017, 5 in 2018, spent 155 days in Thailand in 2018, always entered via business priority)

Currently on my METV (2 entries in 2019, spent 60 days so far in Thailand). My last time I entered in DMK (in economy), saw farangs being taken aside left and right but the IO let me through and didn't say anything.

Now I'm wondering whether I should really spend $13k on an Elite Visa or continue coming in without a problem via business class priority immigration.. ?