I think the distribution elsewhere represents fantastic...

I think the distribution elsewhere represents fantastic opportunity and there are dozens of cases demonstrating this.
However lets say all they need to do is crack ambulances, where they have years of amazing data and as you say, the bulk of the volume.
So what are the blockers that are stopping adoption, they have the approvals, for the most part have the distribution and the device certainly has the runs on the board.
Leaves only 1 issue IMV and again it comes down to direct comparative cost. Address this one issue and this thing will fly.

To be clear, I'm not saying it needs to be the cheapest, its just too far from the other options for the decision makers to consider it.
Thats how the world works and MacGregor needs to get himself across some Price/Volume metrics and understand how big a game changer a competitively priced product would be.
The challenge is appreciating margins at the same time. So get a more cost effective manufacturing environment with the right quality standards up asap and then watch it fly. The current manufacturer would be up for addressing this if a true partner. They would enjoy the spoils of volume just as much.
They are over complicating what is a very simple problem.