Ok, got it. Yes, you can plug the phone jack output of the voipo adapter into a jack in your home, and it will BACK FEED to all the other jacks and you can plug regular phones in those jacks and it will work. No problem.

CAVEAT!!! There is 1 issue however. The junction box on your house where the NORMAL INCOMING PHONE LINE comes in, and then is connected to all the inside wiring to your jacks, MUST BE DISCONNECTED. In other words; you don't want your phone output of the voipo adapter going into the jack(s) of your house, and then being connected to the phone lines going BACK to the original phone company. Their connection could hurt your voipo adapter box. Now; by law; the phone company MUST give you an easy disconnect at your house so that you can DISCONNECT all your jacks/wiring FROM the incoming phone service. This is so you can be allowed to add jacks, troubleshoot problems, etc... Basically, so you aren't at the mercy of the phone company. This disconnect is very simple. It's usually a simple jack plugged in. It's possible that Verizon already did this for you because they brought fiber in and connected phone to your jacks. But you need to ensure this.

What you can do; being you're keeping your fios internet and tv, is keep the voipo adapter on 1 phone by itself until the cutover date. THEN, have Verizon come out and have them disconnect your inside house phone wiring/jacks from THEIR equipment. Then you simply plug into a jack and it will back feed the rest of the jacks. Just don't want to plug into a phone jack if the end of all the phone wires is connected to the phone company's equipment. It will cause problem. Hope this helps. Mike....