The mechanical parameters of two different drivers will not change, but electronic equalization can force different amplitude roll-off behaviour and the phase-response/group-delay characteristics along with it. So, within reason, yes.
The vast majority of speaker drivers (easily available to us today) are designed for some sort of box usage and are (generally) higher motor-strength (low Q) designs. Using said drivers in open-baffle (free-air) configurations means conforming the roll-off to a more suitable rate with EQ.
If typical drivers were used in a "W"-frame application like the Fern and Roby, it would require three different forms of equalization. A 6db/octave dipole correction, a driver Q-correction, and a resonant peak (notch) filter to account for the cavity resonance created by the enclosure.
These fellas seem to have selected a high-Q driver that (sort of) addresses the first two characteristics without the need for extensive equalization.
It seems an interesting design but, obviously, a good DIY'er can create something equivalent (or more likely superior) for much less money.