Hubitat control of HomeKit devices

I Perhaps get a bit confused now that
i am in my eighties. I have some mini HomeKit switches, DIY Smart Switch, that i can control from Apple's Home app.

Can Hubitat control these as well, at the same time, that Siri is controlling them?

No, the integration is one way: Hubitat to HomeKit. You may be interested in the docs where this (and more) is mentioned: HomeKit Integration | Hubitat Documentation

There are some workarounds you can do, like virtual devices plus some automations in the Home app, to get some communication between the two for these kinds of devices. But HomeKit does not provide a way to directly "export" its devices, so it's not quite as easy as you might want.

Download the Hubitat app