You have 2 VZW active lines? If you want to use another SIM when traveling you are going to have disable one, either by removing the physical SIM or by temporarily replacing the e-sim with something like ubigi.

I have t-mobile, they have a virtual phone app called digits. I can set that up and log into it and enable/disable it in it's settings. If it's enabled, I will get all my calls to my normal t-mobile number through that app (and also through the phone if I make the mistake of activating both at the same time.)

I'm pretty sure Verizon has something like that also. Is it "my numbers?"
https://www.verizonwireless.com/support/my-numbers/

With a virtual phone app, your phone number that you displace can be virtual (similar to google voice), and you will still get calls etc on that line, just through the virtual phone app. If you want to use ubigi, just use the Verizon virtual phone app for the number you temporarily displace. When you are done with your trip, restore your VZW e-sim, and disable that number in the virtual phone app.

You may find that you like the virtual phone app for your second number.

ETA, the my numbers faq says they charge $15 per line? Maybe I'm reading it wrong or there's a different app? Somebody here will know.

-David