Yup and yup, respectively.
I have - quite literally - boxes of 'extended range' drivers here, and I have fiddled with them extensively over the past 25 years or so. They have some beguiling* qualities, but when it is all said and done, for me, they don't ever quite cut the mustard for serious listening.
The best use of an extended range driver (I'd posit that there
are no full-range drivers
per se -- given the three orders of magnitude of frequencies involved for 'hifi' reproduction), IMO, is as a wide-band augmented midrange driver.
Electrovoice, e.g., did this in the late 1950s with their "Compact Low Resonance" vented box loudspeakers (e.g., the EV Esquire 200 -- a personal fave in small, high-sensitivity 'monkey coffin' loudspeakers). The sound of the Esquire is quite literally centered on the use of an EV "Wolverine" LS-8 twincone 'extended range' driver as the midrange radiator for the system. The Esquire, again IMO, is the loudspeaker that Col. Klipsch's ear-gouging Heresy could have/should have been
View attachment 64394
https://www.americanradiohistory.com/Archive-All-Audio/Archive-Audio/60s/Audio-1960-May.pdf
EV Esquire au naturel by
Mark Hardy, on Flickr
Mmmmm, sorry, got a little carried away on this topic. I get like that sometimes.
Bottom line for me -- don't muck with the midrange! B)
Even today, there are way too many loudspeakers with crossovers smack dab in the middle of the frequency band which evolution has endowed our species with the most exquisite sensitivity (to frequency, phase, directionality, and intelligibility).