Make the Radiant Heart oath have more weight.

[Red Ropes]

You get a pretty powerful item for being part of the radiant heart, further, you're a order of crusaders who concern themselves with goodly and religious matters. To discourage ring-wraiths, I propose the following:

Make the oath / ring / pin renounce-able without a DM's need to be there.

Make it so if you choose to be part of the Radiant Order you cannot participate directly in a settlement's politics as your priorities are clearly higher. (Like a Sencliff pirate, but, less because you're an outlaw and more that you'd be renouncing some parts of the mudane to persue things outside of it.)

[Irongron]

Two suggestions there, will reject both. If settlements want to refuse Radiant Heart PCs that should be their choice.