Some posts require cleanup from the phpbb format to Discourse, though it looks like topics are locked from editing after a couple months by default:
There is a configuration item, post edit time limit, that limits for how long posts can be edited. It defaults to 86400 minutes (2 months).
Discourse's response to this:
Yes that is a default safety feature. Feel free to set it to years, instead of the default of two months, on your Discourse as needed.
Would it be possible to disable the edit limit as this is a technical forum (and so we can fix formatting and markdown issues with posts from legacy phpbb formatting?)