Reach RTK with Arduplane and Dragonlink

We are trying to get an RTK fix on our fixed wing aircraft running a Pixhawk with Arduplane.

Has anyone been able to send RTCM data via Mission Planner and DragonLink? The bottleneck seems to be DragonLink as the onboard reach shows no data from the base.

We have had the exact same setup on our multirotor work just fine, the only difference is that we use a 3DR radio for the Mavlink.

IIRC somebody said we should use MP 1.3.43 (not newer).
Edit:

We tested that, still no dice. It honestly looks like its the protocol that the Dragonlink is using does not allow for the transmission of RTCM data.

IIRC there were two Mavlink protocols, one for more range (less data) and one with ‘full Mavlink support’. As they are interested in plain telemetry for long distance, chances are high for '…does not allow for the transmission of RTCM data."
You could try to contact Dennis Frie : https://www.rcgroups.com/forums/showthread.php?2571064-DragonLink-Advanced-dedicated-firmware-thread
Please post if it works.