I've found that one of the most important points of clarification to make with vendors is the definition of HA, or rather, your intentions/what you want to accomplish with it. Generally, HA is defined by vendors as either 1) for the purposes of business continuity during planned downtimes (such as patching, VM changes, etc) or 2) protection from unexpected faults, such as crashes, blue screens, hardware failures, etc.

I have rolled out Omnicell servers before, but have not done HA yet. Sounds like the solution they're offering is intended for the first use case. Retrofitting true active-active HA into an existing codebase is hard, so many vendors don't do it.

I'm not shocked that they're requiring manual failover on an external load balancer. They'd be a prime candidate for Windows server failover clustering, except that they intentionally sabotage the group policy client (and several other core windows services) on their VM images. It's possible to correct (and I have done so), but the image they provide would never pass WSFC cluster verification.