I’m a little confused by your question. 
The 32 device limit only applies to non-repeating devices. You can add another repeating device whenever you want (the protocol limit is in the thousands, I don’t know exactly what the smartthings limit is, but it’s at least several hundred.) So if you need more repeating devices, just add those. Then take the hub off power (Including taking out the batteries if any) for at least 20 minutes while leaving all of the other devices on power. This will cause the other devices to go into “panic mode” and when the hub comes back online your mesh network will be rebuilt, with each device picking its best parent under the new conditions.
You should not have to remove a device in order to add a new repeater.