For LTR visa holders, can you book one way flights to BKK once you have the LTR visa and not worry about having to show a return flight? Do they give you any troubles at immigration desk?
TLDR : Answer Summary
Yes, LTR visa holders can book one-way flights to Bangkok without a return ticket. While immigration officers might not be fully familiar with LTR visas, travelers have reported no issues when flying into Bangkok on a one-way ticket. If questioned by airline staff, presenting the LTR visa approval should suffice.
LONG TERM RESIDENT (LTR) VISA RESOURCES / SERVICES