Anyone successfully use Dark Star as primary and warp in multi line (2nd) with Apple Watch in companion mode?

Getting closer to fully moving over after testing out almost a year now. Looking to move from Verizon and already have Dark Star as my backup eSIM on my dual sim phone. Verizon is primary. We have Apple Watch lines.

For me, I want Dark Star for all the goodies it offers and it works well. Can I just get a multi line warp, port my number over and get a free watch line in companion mode? I want to use the same Apple ID. Or does my primary have to be warp and therefor I don’t get all the extras like more hotspot, etc.

Or am I better off making warp primary and dark Star backup and lose the extra features it offers?

I’d port over my SO no problem to warp. Will her watch be free even under the same account or does she need a separate account. I’d like to keep our family stuff tied to one account. I assume hers is easy with companion mode and same Apple ID?

Also have an iPad line. I believe I just use a regular phone line, correct? I’d get dark Star unlimited premium?

iPhone 17 Pro Max, 17 Pro, series 6 and ultra 2 for reference.

Any known issues? While I’m tech savvy, my SO is not and I don’t want to introduce problems for her :)