Jon, the only thing that concerns me in your procedure is the heating time - 22 minutes sounds fast to me. By comparison, here is the profile for the two cheddar recipes I make:
Traditional Cheddar (combo of R. Carrol and G. Caldwell recipes): Ripen at 88°; cut to 1/4"; rest 5 minutes; stir, gently at first, gradually raising temperature to 100-102° over 30 minutes. Hold temp and keep stirring until whey pH = 6.2. Drain and cheddar until pH = 5.3-5.4.
Double Gloucester (Amrein-Boyes recipe): Ripen at 90°; cut to 1/4"; rest 5 minutes; stir gently for 15 minutes; continue stirring and gradually raise heat to 99° over 45 minutes; settle for 20 minutes. (No pH targets supplied with this one, but I'd shoot for the same 6.2 or so at draining, and again cheddar until pH = 5.3-5.4.)
As you can see, the TC recipe calls for 12-14° rise over 30 minutes, so approximately one degree every 2 - 2.5 minutes. The DG recipe is even slower, 9° rise over 45 minutes, so only one degree every 5 minutes. By contrast, you are giving a 16° rise over 22 minutes - one degree every 1.375 minutes - considerably faster, and a higher final temperature as well. I am no expert, but my understanding is that too-rapid heating can cause the outside of the curd to toughen up while trapping more moisture inside. So together with the 1/2" cut you are using, perhaps this is a significant factor in the results you are getting.
On the Lancashire recipe - yes, it is basically a cheddar-ish recipe that is intentionally left very moist - no additional heating, and only 10 minutes of stirring. As a result, the cheddaring process is pretty sloppy, especially at first, as the curd is more mushy than a true cheddar. The high moisture content lets it age quickly, so it is ready in 6 weeks. (And the high moisture content means it is not a good candidate for extended aging - best used within, say, 12 weeks.) My preferred aging method is just to age it "naked" in the cave, regularly turning it and cleaning off any mold; depending on how dry your cave is (mine is always too dry), you will get a bit of a chewy rind that I absolutely love. But if I don't have time to keep the rind clean, I have also vac-bagged this after a couple of weeks in the cave, so that it can age out with less fuss.
If you want an even faster-aging cheese, look for a Caerphilly - ready in 3 weeks! On the forum, I have seen two fairly different makes under this label; one of the makes is similar to the Lancashire make, but with just a bit of heating; it still involves a cheddaring phase, then salting, then pressing. The other make is along the lines of the Amrein-Boyes (200 Easy Recipes) recipe; this involves a little bit of heating (just a couple of degrees), and some stirring, but no cheddaring - just a long time settling in the whey, then pressing, then brining. The result is tangy, crumbly, and salty (though of course, you can control the saltiness by the length of time in the brine).
I haven't tried making either the Lancashire or the Caerphilly with extra cream, but I suppose there's no reason one couldn't. I guess I should give it a try next time ...