What little 5x4 I do I do taco-style.
With Foma 200 I found I would occasionally get a corner of the emulsion rubbed, but more careful agitation sorted that out.
I've used both thick and thin scrunchies, and thick seem better.
You have to be careful not to buy ones which are joined with crimped metal.
I do see slight rub marks on the reverse side, but I can't see any problems with the images when I contact print - however, I am usually making salt or cyanotypes by contact with this size negative, so perhaps it would be noticeable if I were sticking them in an enlarger.
rather like a Paterson v. SS Tank thread, it's clear that some people successfully use taco-style development while others are deadly proponents of trays ... in the end, it doesn't matter a hoot so long as you are getting the negatives you want ... except to folk who believe only the way they do things is the "correct" way, of course