We found Discourse’s default time-limit-to-edit was a bit to restrictive, so its removed now and you can edit old posts. Thanks for the report!
An update on sharing assets, we are really encouraging people to use the community ASSET posts to share their components now, allowing everything to be found and searched in the community feed. The Shared .tox category was imported so we didn’t loose anything of course, but it would be nice to start using the newer location for everything. If you want to feed people into that forum topic for the older conversation and notes, then you could link to the topic from your ASSET post. To create new community posts go to MY ACCOUNT > MY COMMUNITY POSTS and start one from there.