Over the Forum's many years, the only issue that has ever surfaced with using a WDH with the TM swing tongue is that on some non-standard hitches (I seem to recall Curt?), the springbar has a non-standard length, and the tips end up just below the swing tongue hinge. This makes it impossible to mount the spring bar hanger bracket on the TM A-frame. But this issue has come up only once or twice in 20-odd years.
Regarding sway. A WDH in itself does not prevent sway. But as you probably have read here, TMs are designed and built not to sway, so no anti-sway mechanism is required. Some WDHs have built-in sway control, and there is nothing wrong with that, but you are paying for something you don't need.
The cost of a WDH varies widely. Before you take a second mortgage on your house, I would go to pplmotorhomes.com or eTrailer.com, read their tutorials about WDHs in general, and browse through their selection. Many of us use a plain unadorned trunnion WDH from Reese or similar, with 600 pound springbars. It is hundreds less than the fancy ones.
There are also good tutorials from our towing experts here on the forum. Look in the TM Tech Library at
https://www.trailmanorowners.com/for...splay.php?f=42
Bill