So from my testing I discovered that I can still send devices Hubitat->Smartthings. However, I cannot go Smartthings->Hubitat for any new devices (existing devices that were already set up still work).
I started dabling with Home Assistant a few weeks ago and there is an app that allows you to send Home Assistant devices to Hubitat:
This app performs flawlessly to operate my lights originating from Smartthings (haven't tested anything else). There is also an official Home Assistant integration for Smartthings.
So what I do is Smartthings->Home Assistant->Hubitat. I don't notice any performance degradation when I do this and it works for my setup. Just a thought and probably the simplest way to bridge hubs while staying local.
