I've made this other relay now: https://zapbox.fiatjaf.com/

First you have to set up a zap threshold, afterwards anything you publish there will only be shown to people who have zapped you at least that threshold in the past 3 months.

All the rest is the same as a Lockbox:

nostr:nevent1qqsqqqzxnr8xcfku28py2nwvg4p8hh8va7zy0kps6wn9tfld0me8aagpz4mhxue69uhkzet8d9ejuat50phjummwv5hszrnhwden5te0dehhxtnvdakz7qgswaehxw309ahx7um5wghx6mmd9udxdewy