Great note. The grouping (with right incentives) that we can do right now is to open some channels on Liquid and bridge the payments. It's one network. The peg ins are essentially the grouped UTXOs.

Here's how to do it: 
https://juraj.bednar.io/en/blog-en/2023/05/07/expanding-the-lightning-network-to-serve-billions-a-quick-win-strategy/