I moved from a 27.5 dalbello with a silver ID liner to a 27.5 Hot Dogger with the pro liner.
I took the liners out of both shells to compare them. Although the two boots have different BSL's the liners are almost exactly the same size
I felt the FT liners are a little thicker which makes the boot fit a tiny bit smaller but it wasn't enough to change sizes for me.
Hopefully that helps, I am not sure how FT/ dalbello correspond at other sizes and as obviously mentioned it wouldn't hurt to get fitted if you have the opportunity