In the SBOL tutorial, we use a loop for searching for a feature:

for f in i13504.features:
    if f.instance_of == b0015.identity:
        print(f)
        f.locations.append(Range(i13504_seq, 746, 875))

The search through features could be turned into a little macro routine, e.g., def find_feature(matching: Callable) -> sbol3.Feature