Do any of you have experience with through checking bags on PG with separate tickets? (Both flights would be on PG)

I need to fly BKK-REP-KBV-BKK. If I price it as a multi trip, it prices more expensive than if I purchase BKK-REP-BKK and BKK-KBV-BKK separately. If I do purchase separately, when I check in at REP will they check me in and through check my bags to KBV or would I need to pick them and and re-check in at BKK?

Thanks!