Every time I think I'm done, I think of a new improvement to make.
Mk1 transported individual vitae atoms, getting 190 distance.
Mk2 transported a stick of vitae and mors, getting 225.
Mk3, Mk4, and Mk5 changed input handling to build things slightly further away from each other, getting 231.
For Mk6 I finally realised I could build longer sticks earlier by using salt rather than vitae and mors, getting 266.
Mk7 uses these hybrid salt/vitae/mors sticks to squeeze out a few more hexes at the ends, getting 275.

There are many choices for how long to make the sticks. Longer sticks let you transport the vitae faster, but give you less time to do so. According to my (quite imprecise) calculations, one stick of four atoms and one of eight atoms should give me the best distance.