I've been using them and they are a bit touch and go @
Chegs. If I can give you a tip, when you connect the wire to the centre piece, get the rubber insulator back into the housing before pushing the centre back in. I've also had trouble with them if the wire isn't straight so I've got some silicon tubing coming that I'll push over the centre and the wire to stop shorts.
There really should be a decent connector out there but I'm yet to find it too. I've considered buying a tap and die set and making !y own but haven't yet. If only there were bolts available in the right size. I've searched and searched and they don't exist as far as I know.
Sent from somewhere just south on our nations capital.