An NID 4E is a nice gun - I hope you can get it figured out.
I've owned several guns with complicated or supposedly troublesome triggers:
Two 1931 Browning Superposeds with Twin-Single triggers - both of those were tuned before I got them and I never had any issues with either. One of them is now with a friend in PA who still shoots it, still no issues.
AyA Model 53 with a SNST. No issues, ever, and all it ever really gets shot for is clays. Who knows how many thousands of rounds have been through that gun?
The latest acquisition is a gorgeous William Ford BLE from 1908 with a Baker SST. It works flawlessly so far. It's out for a visit at The Gun Spa, getting refinished, recheckered, cleaned right down to its tiniest bits, and dressed up a little.
