Bro sohbuckkong,
Appreciate your update.
So the recent introduction of visa free entry to Myanmar for Singapore passports does not apply to warlord states within Myanmar 555.
From Tachilek you can proceed to kengtung without any permits.
From there you can try your luck but it's a gamble though.
Situation in warlord states always changing.
*Disclaimer: Some busybody and cocky people claim my info and opinion are misleading as out of touch with Thailand. Please use info at your own discretion.