To set up a loyalty program you really need subscriptions that have the same access permissions as most other things in SMF.
If I want to reward 1 year members with cheaper subscription prices I cant do it at the moment without it showing to everyone else. Of course ... people try and subscribe if there are lower prices, regardless of whether they are entitled to it or not - need group permissions to access certain subscription options for loyal members.
Well, this was raised on Github, https://github.com/SimpleMachines/SMF2.1/issues/269 - where I outlined much the same requirement as you did, but apparently that's not what's needed.
Yes thanks for the reply and link. there does seem like a lot of divergence in opinion but its a useful to offer renew discounted. I will look into using the start up fee alternative.