@helene fwiw ld sigs are recommended against and were only implemented for relays, which people largely don't even use anyway
if i were doing a greenfield project i simply would not bother, as i find relays conceptually flawed in their current form and also i think you can generally trust what was sent to you without having to verify it 100% -- like, have the relay do the verification before sending it out, then implicitly trust the relay