Flew to DPS a few times but unfortunately cannot remember if they separate arriving and departing pax. I do believe so - at least in Jakarta it is like that. Again, in DPS I do not know if they have a connection lane allowing you to stay airside for transfers, but in Jakarta going from a national to international flight I was channelled through the main check-in hall, so this suggests they may not have it in DPS either.

In that case indeed you would have the whole shebang of passing immigration into Indonesia and back, and security. If you have an e-visa on arrival (Europeans pay some 20-30 Euro for that) and have a passport of one of the many eligible countries they have e-gates though that work quick. If the plane is only 1.5 hours on the ground or so things will be tight though. And do not forget you need to fill in an electronic declaration for the luggage you bring in, which gives you a QR code - that check is a breeze if you have it, but otherwise you lose another 5-10 minutes typing on your mobile if you have internet, or waiting to use the few computers they may have put in place.

Edit: XP run, I presume?