Strings. It’s all about their tune and tension, right? We use Daddario flat tops, their resonator set, but replace the high 16 with a 15.
The flat tops are just phosphor bronze strings that are polished. A bit warmer but much less string noise. String noise is more noticeable on your resonator because everything is more noticeable… they are LOUD. I put flat tops on any guitar now though too.
They are heavier gauge strings. This allows some more tension when tuned to open D and playing slide. It warms everything up too. You CAN tune to standard but I suggest tuning down a half step- it lets everything vibrate.
These are short scale guitars and using heavier strings will give you the most versatility. If the strings are super heavy it will be slide only, if they are light it will be fingerpicking only. The heavier strings allows us to set a resonator up will a very comfortable normal acoustic guitar action so you can play whatever you are inspired to in the moment.