Are you are looking to use your TT setup and as a base for road position? If so, I don’t see that as helpful in most cases. Differences in saddles, saddle to bar setup and predominance of using the aero extensions in TT are drastically different from a typical road setup. You can get a basic saddle height as a starting point, but setback and actual saddle use will likely mean it will be different in the end.
Options for starting “from scratch” include using one of the available apps:
Or you can check out a couple of the links under “General Fitting” in my OP at the top, as other starting points.