Is Liquid and that side chain ready for prime time? You set up on Green wallet thinking there is a peg into L-BTC but then you have to get another app called SideSwap. Getting two apps maybe too much friction. I thought that would be inside Green Wallet but that coulf open up more attack vectors.
Discussion
Try ecash
You send from lightning wallet to ecash wallet simply in and out
Your overthinking it. 4 sure. Simplicity and need is the mother of all invention.
Ah the liquidity looks shallow. Just messing around with small amounts. 
Nope this is what AQUA wallet solves. Green is i believe looking to integrate it into if i remember correctly