Great topic. Noggins, well… sometimes called blocking.
I take it the your “Span” refers to the joist not being supported except at either end. In this case there is nothing wrong with assisting the natural twist that you can quite often get. Its quite simply your choice and considering weight distribution I can’t see the effect making much difference. This said I am assuming that your beam span and joist span are correct for the size of timbers that you are using. It is advised that for clear spans over 2400mm the the use of noggins add to the stability of the structure, they would be placed in the centre of the span at the 1200mm point.
By using clean/fresh c16 – c24 certified timber joists the twist is reduced to that of aged timber in your not so used timber yards.
The treatment that he showed (I didn’t see the show) I can’t comment on as I don’t know the type of timber he was referring too or indeed that of which the timber was treated. All cuts for exterior softwood timber should have additional treatment applied to enhance the longevity of that peice of timber. Do consider, perhaps you are already aware, that the most exposed part of any timber is at the end grain where it has been cut.
Advice changes all of the time and do remember there are only guidelines/advice for timber decking and nothing in any regulations unless the deck is “part” of a new build. Or if you have consulted a structural Engineer for direction.