Well caught, it should read \sethook{...}{id:GEN}{}
Are there start/end hook-points on periphs? The answer is not yet.
I can see how {start} and {end} would work, but setting a {before} or {after} on a periph seems like it would be ambiguous. Should it occur before the periph definition or before the periph invocation? (e.g. if you set it on {before}{periph:intnt} does it occur just after Malachi 4:6? after the page break? or at the end of the previous periphery in the INT book?)
And if someone puts a {before}
hook for the coverfront
periphery (contents of the front page), where should that go?