No truth to that at all. On the 18th, I was denied a 5 year Thailand Privilege "Formally Elite" visa at Suvarnabhumi. I had 3 Thailand Privilege staff with me to inquire the reason. The only reason given was "I traveled to Vietnam for 2 days and that looks suspicious.
I paid 1,000,000 baht in 2019 for the 20 year Visa option. If 1 million baht and 3 Thailand Privilege agents were not able to change inmigrations decision, I highly doubt a 8K baht service has more power/influence.
* I was given a 60 visa exempt entry and Thailand Privilege has suggested I go to CW immigration #1 in a month and try to get my 5 year Visa there. Point of my post is, paying an agency does you nothing if your flagged in immigrations system.