Yes you are correct. Also mid sized ATC like the ATC 100, JBL and other big boxey three ways tend not to image (or disappear) as well. It all has to do with mid range and tweeter frequencies because the LF sound wraps around the entire speaker (wavelength is much larger than the woofer)
I did not mention but a waveguide around the mid range or tweeter can create directivity and reduce the baffle issue too. ATC mid range has a waveguide and so does the tweeter but nevertheless the smallest models image best. A horn works well too like Avantgarde.
Audiophysics really do the disappearing trick and so did Bose Acoustimass although the audiophysics are a fantastic speaker and Bose is average but you get the idea....
It is more the disappearing act than imaging that is most immediately noticeable...
Genelec have done a lot of work on this
https://www.genelec.com/key-technologies/minimum-diffraction-enclosure-mde-technology