I understand your frustration, and when it comes to support and further development being dropped for the Cobalt, we share it in spades.
On dives with a max depth of over 150' / 45M the Cobalt has fully switched to "iterative" RGBM, which will give a series of short stops starting at ± half of max depth. That was defined by the algorithm Atomic chose for us to implement.
If you can wait a bit, we're working to put together a new computer configuration that we hope to offer to Cobalt users as an "upgrade"- essentially recycling your HP connection but replacing the main PCB, screen, and case. While we will still include RGBM, we have implemented Buhlmann alongside, with the ability to switch between algorithms on the fly. As an independent effort, I don't want to promise anything, but we're very aware of the many Cobalt users who may have interest in an updated version, and we're working with some types of manufacturing that should allow us to do this even at small volumes. You sound as if you would be our ideal intended market.
Keep in touch, and we will be making any announcements via our ScubaBoard page,
Ocean Concepts
Ron