Thanks for the suggestion. There are probably a lot of things that one can set in the Document Grid that would be nice to set at the time of transition list import. You've given us something to think about.
For now, you could add a "Note" column to your transition list to indicate whether each transition is supposed to be quantitative. After importing the transition list, you could use the Document Grid to filter for all transitions with that particular note, and then use the "Fill Down" context menu item to set the Quantitative column to the correct value. It's not ideal, but it's hopefully a decent workaround.
Thanks for using the Skyline support board!