You don't want to use a HA filter, nor a white light filter, during totality. You photograph totality without any filters at all. A lot seem to do this with HDR technique to get the range captured in the small period of time that totality lasts.
Of all the points up to totality however, HA or white light is how you do the partial phases of the eclipse. They market for this part of th eclipse and that more and more eyes will be looking towards the sun as that event approaches. Just because they're not used during the shortest phase of the entire eclipse, totality, doesn't mean it's not still interesting to view or photograph the partial phases up to that point.
Edited by MalVeauX, 13 April 2017 - 04:47 AM.