WHMCS does not support grace/redemption periods & fees per registrar for the same TLD.
You must use custom hooks or a custom module.
How to solve it properly:
Keep one TLD config (lowest grace period + highest fee as you’re doing now)
Use a WHMCS hook to:
Detect the domain’s registrar
Override the grace/redemption fee when the invoice is created (or when the action is triggered)
This lets you apply different fees per registrar, even with the same TLD.
Not possible
No native WHMCS setting
No per-registrar TLD configuration in core
Recommended approach
Custom hook (fast, reliable)
Or custom registrar module (best long-term)
If you want, I can give you:
A ready-to-use hook
Or a simple design for a custom module