I have never been through Makassar but I would be inclined to overnight there if others on the board say it is a reasonable place to do an overnight layover (Jakarta is definitely easy place to do an overnight layover, hopefully Makassar is also). You are going to have to overnight anyway, it may as well be one stop from your final destination (and it gives you a comfortable connection before Nabire as opposed to a tight one via Sorong ).
Despite what I just said , I would say you probably would have about a 75 percent chance of making the connection if you went through Sorong. Garuda is fairly reliable and Sorong isn’t a big airport. I assume you will have to claim bags from Garuda and re-check on Sriwijaya so that does eat in a good chunk of your connection time. If you do this you might want to use a porter , they sometimes seem to skip part of the check-in line. Bottom line is you will most likely be OK, but even a 25 percent risk for a screw up isn’t a fun way to start your vacation . Since you would be switching airlines at Sorong, that makes things more complicated if you and/or your bags miss the flight. If you miss a connection with the same airline at least they know what happened and are generally accommodating, missing a flight on Sriwijaya because Garuda was late might be a giant PITA to sort out.
It kind of relates to your question , but I would kind of be interested in the experience from others on the board as to how far in advance of departure time the baggage check counter closes and how far in advance of departure time they typically start boarding the plane .
It seems like some of the official Indonesian airline recommendations for arriving at the airport early are similar to US airlines but in reality it seems like some people check in and check bags much closer to departure time than I am used to (especially in smaller Indonesian airports). It also seems like boarding often begins very close to scheduled departure time (as opposed to 40 or 50 minutes before in US). Maybe it is because the flights often run late , but it just seems like I tend to stand around waiting to board for a lot longer in Indo than other places because they only start boarding a few minutes before the scheduled departure time. Seems like a couple of times a liveaboard cruise director suggested leaving for airport from boat with way less buffer than I would normally allow (I and other passengers asked for an earlier ride to airport than suggested ). I just don’t have a feel for the pattern. Just to be clear , I am not advocating to cut things close- just trying to better understand the buffer I might have if I get hit by an unexpected delay before check-in and/or boarding
