Comment by pants2

To some degree this is normal - for example I worked at a med device startup where we got investment from one of our manufacturing partners. That helped with growth which in turn meant more manufacturing work for them, and presumably they'd be happy to invest in another round and keep the flywheel going as long as there is some real outside demand.

I honestly think it's a great model for incentive alignment and not that sketchy on the surface. For the manufacturer, it's guaranteed revenue with upside convexity. For the startup, it's better terms and priority from the manufacturers since they have a stake in your success.