...kamraten... กมรเต็ง ว่า กะมอนเต็ง แต่นานๆไปผมชักเอะใจว่า อ่านว่า กม-ระ-เต็ง ก็ได้...

This reminds me of the word ระเด่น (in the famous ระเด่นลันได) possible from Java. "raten" refers to a member of a noble clan; a prince or a pricess. "raten" may come from "rata" (participle of "ramati" = love).

The prefix "kam" may come from old Sanskrit "kram" (Pali "kama") written in Thai alphabet "กรม" (and read "[โ]กม").

By this line of thinking, kamraten is กำ ระ เด่น = a truely loved/adored person/gentile ที่รัก[แท้]. So "Vrah kamraten an Sri Jaya-sinha-varmma..." is just "highly praising title".

But to bring in Javanese words would open another can of worms ;-)