Alfine (Di2), compatibility

Hi all, I intend to install the Alfine 11 speed hub on my recumbent. It will be either mechanical or Di2. If anyone can help with the following, I would be grateful:

  • Do they make grip shifters for the mechanical Alfine? My recumbent has underseat steering, so a normal trigger shifter won’t work. You hold the handlebars in each hand, with the bar end at your thumbs. I’m using bar end shifters for my deraileur gears.
  • How well does Alfine shift under load? I know it isn’t ideal, but that is what I am used to and it could take me a while to learn to avoid it.
  • Can I use Di2 triathlon shifters like these alone with the Alfine? I know they work in addition to drop bar or trigger shifters; but I won’t have either of these.
  • Will Synchroshift work with the Alfine? Supposing I have the 11 speed hub at the back, and a dual chainring at the front.

Many thanks!