No. Its classified as a main branch and very Expat friendly. There were 2 other Expats getting letters for Imm while I was the there. Asst Manger Khun Sombat has a long history of sorting out any problems and staff all speak English. Been going there over a decade.
Got bank letter and 6 months statement,100 baht each, from Bangkok Bank, KSK, in CM yesterday, took 10 minutes,same every year. Fixed account. Valid for 7 days. Off to IMM now for renewal of Marriage extension. Avoid satellite branches in malls is my advice.