I wouldn’t leave them hooked up permanently. We are not running full race engines where the jetting goes off of the sun goes behind a cloud. Just use them to jet your carb and then take them out. You’ll be tuning for “proper” operation (on the rich side) and this means more deposits than O2 sensors normally like, which will reduce their life.
I disagree about where to place the priority when choosing a gauge. The suggestion of PLX above for example. Lots of complaints about lack of support and a poorly designed app. You want a company that supports you and their product, not a 10 minute tech wonder. It is difficult to get meaningful info off the web and review sites are over represented by unhappy/ignorant users. Feedback from people with personal experience, and have used their equipment a lot, is much more useful.
Lastly, a blue tooth link would be very handy but how well does it work with unshielded electrical systems? Just be a little cautious.