I would just echo all of the anti-sentiment towards investment shares, etc. If a ball and chain is not necessary than Framework should do what they can to avoid one.
Simply the best thing you can do for Framework is word of mouth. Tell your family, friends, and neighbors. Use your internet presence to talk about and encourage it.
Every sale is another customer that has bought into the change; that now has a tangible commitment to it. They will either buy upgrades or spare parts, or they will continue to use their laptop for much longer than a traditional laptop they might have bought instead.
This is how Framework is successful. All the talk and buzz in the world doesn’t amount to much if sales don’t happen.
If you want parts and stuff to be available for decades then sales must happen.
Nothing kills a GREAT idea like the lack of sales.
Fortunately, Framework seems to be doing great in this department!
That all said, I think getting official support from Linux distros would be pretty big. Fedora and Ubuntu should publicly endorse and certify the Framework laptop.
It is encouraging seeing Elementary OS on these forums essentially doing that very thing.