My DTV journey has finally come to a successful end (although it did take a bit longer than I hoped/expected).
Applied on March 15 in Kota Bharu, status updated to "processing approval" on March 27 and visa approved (unexpectedly) on Saturday 12 April (which according to all available information should be a day off both for the Malaysian Thai embassi and the Thai officials in Bangkok).
Upon entry to Thailand I got invited to a "private room" for a conversation but everything was very (unexpectedly) friendly, especially after the IO found out that I can communicate with him in Thai. After about a 5-10 minute chat I received my first 180 day stamp and was on my way.