Threads in plastic are not one-size-fits-all
"Just print the threads" works for some joints and fails quickly for others. A large, coarse, rarely-engaged thread in plastic can hold up fine; a small, frequently-engaged, or heavily loaded thread wears out or strips within a handful of cycles. Four real strategies exist between those extremes, printed threads, a heat-set insert, a through-bolt, or captive hardware, and the right one depends on thread size, how often it will be engaged, and how much load it actually carries.
How the plan works
Small threads default toward an insert unless the load is light and engagement is rare, in which case printed threads are viable. Heavy load or a large thread size favors a through-bolt, the strongest option when both sides are accessible. Frequent engagement at other sizes favors an insert for its durability; occasional or rare engagement at moderate load favors captive hardware, a reusable middle ground that only needs one-side access.
Worked example
A medium (M3-M6) thread, occasional engagement, moderate load: the tool recommends captive hardware, a nut trapped in a printed pocket, as strong and reusable as a through-bolt but without needing access to both sides, with a heat-set insert shown as the alternative if engagement frequency turns out to be higher than expected.
A common mistake
A frequent error is choosing printed threads for a small size purely to save the cost of an insert, then discovering the thread strips on the second or third use. For anything beyond a single, rare engagement, an insert's small added cost is usually cheaper in the long run than reprinting a stripped part; weigh the reprint risk, not just the upfront hardware cost.
Limitations
This compares threading strategies qualitatively based on size, cycles, and load; it does not calculate actual thread strength or pullout resistance for your specific hardware and material. Test a sample boss before committing a load-bearing threaded joint.