Thanks for posting this. Hope all is well.
There are some bad habits developed with this type of sparring such as the obvious examples of leaving the head and face open to quick hands, elbows, and head butts. But it's a very good exercise for conditioning the body and demanding more of a practitioner's martial repertoire.
I second that, Bill. It is a type of sparring that is very taxing on the 'wind' and heavy on conditioning.
But as you say, it must used carefully and not too often as it will ingrain bad habits.
As it is, we see Uechi people leaving their faces wide open...sometimes leading with their faces...in Dan tast sparring and even some tournaments...and the resulting 'face smacking' and the 'indignation' of the 'smackee' ...after the hit.
When most of the practice is confined to 'blocking' punches to the body...the brain begins to think there is a 'force shield' around the face and it refuses to protect it.
A fact most Uechi people will continue to deny...until you put gloves on them and ask them to see how well they can do against a kick boxer.