Sorry its a 650 so I have incandescent bulbs which are not very bright in my opinion. And as far as the relay, looking around unless the relay is LED specific when you plug a LED in you get hyper flashing. These bulbs I bought are suppose to eliminate that need with a built in load resistor but it doesnt seem to work so i want to try a different relay before sending them backIs yours a 1050? The 1050XT already has LED indicators so I would expect it should be possible to change to LED. I don't understand the LED relay statement. A relay is generally only required when you want to switch higher currents that the original switch was designed for. LED's will invariably be less of a load than filament bulbs so a relay should not be required. I can imagine that some messing around with resistance values for your particular model may be required to get a generic LED flasher to work correctly?
I assume I would ground it to the negative side of the battery.Change the relay to the three pin LED rated and ground the spare pin (run an extra wire to the battery).
If you do anything else (non-LED relay) or a LED rated 2 pin relay the flash rate will be unstable.
I have that setup on my 2014 DL1000 with a CAREFUL choice of LED replacement bulbs and it works well.
If you use bulbs, you also need to put a THIN smear of silicone adhesive on the side when you install them. They are heavier than the spec'd bulbs and will wobble and wear away the connector at the base otherwise. A thin smear of silicone and they can still be pulled out if need be.