You're right that the Roedale is only for Varmints.
I tested the HSS last week after my Tubb's Final Finish experiment. It was very effective at reducing muzzle flip. As far as accuracy goes I was unable to tell since the Tubb's Final Finish eroded my lands to the point the bullets were jumping too far.
I've since reseated the bullets and hope to test it for accuracy shortly.
When it comes to muzzle brakes and accuracy I am cautiously skeptical.
Even if it is threaded onto the barrel, unless your smith aligns the brake with the center axis of your bore, gases will place uneven pressure on the bullet as it leaves the muzzle. The clamp on brakes seem to have a much looser seal around the bullet as it travels through the brake to avoid being damaged if the user failed to install the brake properly.
Hopefully I am proven wrong with the HSS brake when I test it for accuracy. The machining is excellent. The finish falls short of what I would release, but that is more cosmetic for a varmint and target gun that is not exposed to harsh elements.
More to come as I have more data to report!