Yeah, but why not. The speculation all adds to the rich tapestry of life.

Plus, if they do manage to turn up something, hell, I'd find it exciting.
If you have a butchers at google earth satellite view, there's a tantalising not quite circular Hillfort to the North, North East of Craig Rhos-y-felin, prob a click or two, which is listed as Castell Mawr on the map which is the report below stats as late Neolithic/Early bronze Age.

Nice little illustrated PDF about survey and history of it as well as a few other defended enclosures to boot here....
http://www.coflein.gov.uk/pdf/AENT17_06/
scroll down from title page, starts on page 2. Not saying it is this place at all, just looks interestingly circular.

ANd when you read stuff like this...just adds to the possibility..

"Unlike these (other local defended enclosures...my words) Castell Mawr does not enjoy a particularly defensive location, although there are distant views in all directions. To the south the view encompasses
the Mynydd Preseli and includes the hillforts of Foel Trigarn (Baring Gould et al 1900) and Carn Alw (Mytum and Webster 1989) together with the outcrops at Carn Menyn (guess it should read Carn Geodog now) from which the Stonehenge bluestones came."

And what does this suggest to you...

"The defences of Castell Mawr are also unusual for Iron Age sites in the region in that the main bank seems to lie outside the ditch"

And further more...

"It would seem, therefore, that the main enclosure at Castell Mawr does not sit
comfortably within the spectrum of known Iron Age settlement forms in south-west
Wales which suggests that it is of a different date. The site can be interpreted as an
earthwork of two phases. The first phase consists of the large enclosure defined by the
large ditch and external bank. The second phase includes the construction of the
cross-bank and possibly the small inner bank of the main enclosure.
The first phase would appear to have similarities with a henge monument, particularly its size, situation and the external bank. The classic henges form a group of prehistoric monuments that have proved extremely difficult to define rigorously (Clark 1936, Atkinson 1951, Wainwright 1969, Burl 1969, Catherall 1971) and the most recent survey, incorporating much aerial photographic data, has suggested that many do not belong to the “classic” henge series, but may be considered related (Harding and Lee 1987). The terms henge-related or hengiform have been applied to such sites, and this
would seem to be the appropriate label for the Castell Mawr phase one enclosure. Such sites are rare in south Wales"

Mmmmmmmmm, hengiform (said in a Homer voice).

Though on the other hand....

"One interesting feature of some henges is the presence of arrangements of uprights, whether timbers or standing stones (Harding & Lee 1987, 42). If any such arrangement of stones were originally present at Castell Mawr no sign was found on the ground or by the geophysics."

And then again...

"The site lies under 6km from the source of the Preselli bluestones used at Stonehenge and might even have been the prototype for the bluestone phase there."

Having just read the paper in Antiquity (that's the journal, I'm not a time traveller) im left frustrated, not so much by what has been presented as evidence for quarrying at cryf, but by my inability to be able to identify its importance. I want to discriminate, but I haven't the tools, if you will. We (the punters) have little option but to assume the blocks underneath the 4m long recumbent, for example, are of importance, because we are told they are. Are they different in any way to other bits of stone in the vicinity? What makes them not just bits of stone that were on the surface when that stone was moved/fell/slid into its current position?
The levelled platform, the diminutive stones standing in pits, the dry stone walling, how much do these really tell us about quarrying? They have been dated and they indicate activity at a certain period, but I can't satisfactorily work out their relevance to large scale quarrying of stone.
The recess isnt dated, and it felt weak to have to mention th Neolithic occupation site "only" 1.5 metres from it. It read more like "come on, that's got to have something to do with it, eh?".
Suggesting bluestones were perhaps brought to Salisbury plain much earlier to cope with the very inconvenient boles barrow feels similarly desperate. Looking for a monument between the two sources is just flailing around in my opinion. We can all construct possible scenarios.
Ultimately, I don't know how vital some of these quarrying "indications" are.
But I also know there is no current evidence 'bluestones' arrived on Salisbury plain from hitching a lift on a glacier.
So, I'm still romantically attached to the image of human transportation, but no closer to really believing it. However, in the absence of any decent alternative, it's where my bet would be placed.