[drdeca]

Assuming you aren’t communicating with those not on the ship while in the ship, the only difference with warpfield is that the trips take longer for you? (Your trips take same amount of time for others)

If you go to Europa and then head back, Joe here on earth will have aged the same amount by the time you get back. The only difference is whether you aged the same amount as Joe, or less than Joe did.

The warp bubble doesn’t make you miss any more of Joe’s life. It just changes what ages you are when you experience the parts of Joe’s life that you do. (Specifically, warp bubble makes you age more quickly, same rate as Joe)