As currently sold, the retrofit alarm kit, while a nice concept, is so anemic that its practicality is seriously impaired. Battery operated, it can accommodate only 2-wire alarm components, which all but limits it to door and window contact sensors. In order to do an effective takeover of a house with a pre-existing hardwired alarm system, there needs to be a way for it to handle 4-wire sensors as well. That way it can also handle motion detectors, glass-break sensors, smoke alarms, external sirens, etc. There already exist products on the market that can do this (such as the Konnected alarm panel), so it is not a question of the technology not being around. If I could find a third-party product that interfaced with the Ring system, I’d go with that, but I can’t find any. Hence I’d like to request that Ring at least make a version of its retrofit kit that can incorporate both 2-wire and 4-wire components.
I posted another request to add normally open contacts to the retrofit kit. I had forgotten about the other 2 power wires for smokes and motions. It’s possible to provide that power from an existing alarm system, and it would be much more expensive to make the retrofit kit provide power, so I think these can be separated into two issues. But this is a common problem many people will run into.