It might be interesting to persist the board size per-view instead of persisting the size across the entire site.
One thing I've found a bit awkward on desktop with old and new designs is that I prefer different board sizing on different views in the app - particularly the analysis board, I want to see the computer analysis above the fold, so I end up downsizing the board in that view to be able to see that, and then increasing the size of the board during play just so the crosstable is above the fold.
I used to do this by holding control/cmd and rolling the mouse wheel to zoom the entire window on classic; now I need to resize using the corner control - a bit less convenient.
Good work on the redesign - as a developer myself, I know how necessary these things are and how users can be very reluctant regarding change.
You can't post in the forums yet. Play some games!