I am not at all averse to being educated on this topic; just why was British
support for the Calabrians pulled?
Reference to good literature might be a good start.

Heavens; and all this time I thought I was doing a great job of providing references and quotes, even quoted what general Fox wrote on the subject, in this thread. But, these forums aren't really made for clarity or continuity. In any case, the book I think you would find most useful would be

"The Battle of Maida -1806" by Richard Hopton (2002)

Hopton addresses the history-of-the-history regarding the column vs line issue( that you and kk were sniping at each other about.) He comes down on the side of the French being in line but it really helps to read what he wrote in it's entirety.

The idea of Stuart's "Descent on Calabria" was nothing more than a quick hit-and-run operation, as you suggested, is, I think, put to rest with:
Hopton - p. 138

"On 7 July Stuart issued orders for the return to Sicily and Oswald's brigade set off towards Monteleone that day, the rest of the troops following later. Stuart may have abandoned the idea of pursuing the beaten French, but he had not forgotten the original aim of the expedition. The army would march south and complete "The Destruction of the Enemy's Establishments on the Shores contiguous to Sicily". Capturing the French strongholds in southern Calabria in order to retard or postpone indefinitely plans for the invasion of Sicily had been one of the objects of the expedition from the outset and now, with Regainer retreating to the north-east, the French strongholds were at the mercy of Stuart's army. The victors of Maida could now reap their reward, the lasting security of Sicily."

Why did the English generals pull their support for the Calabrian rebellion? Well, that's sort of where this entire thread started. My view: it's complicated. There's no single text to point to that properly covers the issue. Think I've already mentioned most of the important texts in this thread. I'll see about putting together a bibliography.

Still haven't caught sight of my Russian 2nd Lieutenant of Artillery, Figner, but, it feels like I'm getting closer. Almost certainly, he would have been actively employed by the Court of Palermo to make espionage missions into Calabria/Naples. With his ability to speak French, he's a perfect candidate for the Queen's favorite endeavor: espionage. What I need to find is a book something like: Court of Palermo 1806-1807 Military and Espionage operations in Calabria. If it's around, it's probably in Italian. Probably need to look a little harder for something from the Russian side of things regarding the 1805 Anglo-Russo Lacy/Craig expedition that almost certainly brought Figner to the scene.