these knots resemble the tying of the Jamming Bend!, ABOK 1471;
so, to apply the description to these quasi-bowlines:
This quasi-bowline is tied with the working end tucked through the modified marlinspike hitch; both ends of the hitch are pulled, which engages the working end, and the quasi-bowline is formed in the parts of both.
the description of the Short End Bend, ABOK 1473, describes the end as being ‘swallowed’.
the term jamming bend seems to mean this mechanism where the end is folded / scrunched into place?, hence the name ‘jamming’; it could very well be a general term? i have been looking at 8 variants (and more) of these q.bowlines and their bends, and some of them appear like-to-jam!