I have my Nuki lock so well protected in my Nuki app. But when your lock is in Homey it is easy to unlock your door without any protection.
When your are still logged in at your PC this can be a risk.
It can also be solved with a biometric authentication before entering the Homey app
If you have an iPhone, it is possible to require Face ID before opening a specific app. I don’t know if Android has a similar feature though.
Edit: Didn’t read the PC part.
I understand your thinking, but if “still logged in to your computer” is the part that allows people to control your home, then I think that’s not the only think you have to be scared for. I’d say there probably is much more to find on your PC that’s at risk at such point than just opening a lock.
On Mac there are apps like AppCrypt that can lock apps - no experiences with the app myself. Perhaps there’s something similar in Windows.
My best suggestion would be to memorize Cmd+Shift+Q on mac or Windows+L on windows and make it a habbit to lock your pc no matter what short break you take..