Hey @happybuilder thanks for tagging @airdev on this! 
We’ve been participating in early trials, and think the new responsive engine is going to be a huge step forward. The new engine is more intuitive and allows for better handling of common responsive layouts, and should ultimately cut down on lots of time and hassle. Here are a few thoughts on how we’re approaching it. Happy to answer questions about this (including here in this thread):
- We are not moving to the new responsive engine yet. There are still a few open feature requests (e.g., “padding” and flexbox “gap” controls) that we are waiting on, and we want to make sure everything is stable. We have a plan in place to fully migrate and map everything across the board to the new model, but it’ll realistically be a month or longer to get there.
- In the meantime, the old responsive engine will continue to be supported, so there shouldn’t be any issues when using the current Canvas library.
- From our early tests, we believe that it will be easier for Canvas users to manually recreate more complex pages with the new responsive engine instead of converting them (for pages where that makes sense). We’ll come out with more guidance on how to do this.
Overall, we’re extremely excited about the new engine; it’s a huge step up from the current one and supports new and exciting features that aren’t possible with the existing engine. We’ll definitely keep everyone posted, but please don’t hesitate to let us know if you have any questions!