I've been watching your thread for several reasons and I liked it.
However, though I would love to have the possibility to play as saint Venceslas (which unfortunately you don't allow as you give the throne to Boleslav already), I am also little more in favour for a later bookmark like 955 or 962 in regards to western part of the map.
As King said, we still haven't got far in this, I would like to make a timeline for our needs where we would put interesting periods for each region and accessibility of historic rulers for each region and then we will decide. And as stated above, this - I'm affraid - will put the 935 bookmark quite down the list.
Sadly while your work on the submod is awsome, it wouldn't be that much of help for us if we just canibalize it, due to the different map and many other things, even though I am sure it would be way better than adapting the vanilla characters and title history.
Frankly I would really love to have 3 new bookmarks in this hole, 855/862 or something around them or possibly little later, something between 999-1005 and then the Dandanqan battle in 1040 with Ghaznavids just after their zenith, Qarakhanids yet united and Seljuks just taking over Khorasan, with Buyids still holding much of western Iran sharing it with few other interesting minor Iranian dynasties.
But with the overhauls still ahead of us, the entire later game and other stuff, one extra bookmark will be enough to start with.