... Do you guys think there is still substantial melt going on, but the pack is being spread out so that its extent is roughly the same? ...
We do indeed. See, when ice fragments enough, some wave and wind actions often disperse pieces over greater area than initial "one big solid piece" occupied.
But personally i think it's something else being major factor here. The "extent" total number includes regions with as low as 30% ice concentration (in some systems - even as low as 15%), you can see how this can compensate for loss of ice due to melt because of the above paragraph. Some areas "slush" into larger extent, others "ice covered" in extent-sense areas - shrink as ice melts away completely, and when there is much former and not too much latter, extent numbers can stall for a while.
Check "ice area" numbers if you can. They tell a bit better story, overall. Still far from perfect, of course. Volume numbers are IMHO the best if one wants to know "how much melt is going on", but sadly those are hardest to get, larger uncertainty, and way less sources, especially near-realtime.
The opposite thing is noted too, with varying scale, every melt season: i.e. when big areas of "low concentration" extent happen to "cross minimum allowable concentration to be counted as ice extent", - then we see extent numbers dropping multi-hundred thousands square kilometers per day without correspondedly intensive real physical melt going on. Usually that's a thing for way later in a melt season to happen.
Basically both sorts are mostly quirks of the calculation method called "sea ice extent" rather than real physical processes, i think.