So there are two paths to conversion. One is just publishing all the shapes of bases (curved, angled, etc) with openlock slots on them. That is a path forward for anything OpenForge 2.0 that can take bases.
For the older stuff, crenelated, sewer, pool, ruined, stone, I'm slowly making new sets that fill the same niche, but with the lessons I've learned over the past few years.
New sets as I create them, I'll just create off the bat with support for both systems.
I expect it will be about a year give or take before everything is available in both OpenForge 2.0 and OpenLOCK styles. I try to get stuff moved over, but I also want to make sure that I'm publishing new stuff as well. So far my pace has been a consistent 4 releases per month for most of the past year. About half of those I'm doing as updates, and about half is new content.
If there's something specifically you want to see moved forward, my patrons do have a page where they can vote on what I should be working on, and I pretty much always pick from the top 5 or so for what to work on for most releases. Votes are done on this page: http://openforge.masterwork-tools.com
I do still try to get things people from the community want, but I since they are supporting me, I generally give their votes priority.
As for the specific question of sewer - I'll try to convert them, but they are more difficult. The problem is that the sewer is 'below grade', so it interferes with where the clip is. I can move the contents up, but then it gets to be a little odd that the flowing sewer is higher then floor tiles connected. I'm sure I'll come up with a solution when I work on it, but I've been noodling on it in the back of my mind for a while.