When I purchased tickets via the app, the temple tickets were sold out for the day I wanted, so I was forced to buy a Borobudur park entrance ticket instead. However, when I went to exchange my ticket, I was given the option to upgrade to the temple, allowing me to purchase an additional ticket on the spot.
Borobudur itself is quite nice overall and worth a visit. However, I have two suggestions for the management. First, after disembarking from the temple, there should be a free shuttle to the exit, just like the one provided upon arrival. Instead, we have to walk to the museum first or pay extra to rent a golf cart or minibus, even though the exit is quite far and hot.
Second, after arriving at the exit, visitors shouldn't be forced to take a long, winding path through vendor stalls. This makes us and many other visitors increasingly frustrated and discouraged from even stopping to check out the merchandise. The exit route should be made as simple as possible.