I think arguments could be made for each version.
So, the conventional deadlift is more back-centric in general than a trapbar. With a trap bar, you have a shorter range of motion, and you engage the legs more. But because of the leverages on the trapbar, a heavier load can be used, which is arguably going to be better for yoke building, specifically. Then you have the opposite end of the spectrum with the snatchgrip pull. Out of all 3 of these choices, I ‘feel’ my yoke area working more on this lift than any of the others. It’s absolutely brutal. I’d recommend using straps for this version, assuming you’re not also performing this as grip work. I’m tempted to say that the snatchgrip would be my preference, then conventional and trapbar being essentially equal. But I can’t go all in on that, because I’ve never performed snatch grip deadlifts regularly in my own training. It just seems like the way to go to me. And the way I would do it would be to incorporate a shrug at the top, so using a slightly lighter load. I don’t know if that’s considered a high pull or a low pull… I think it’s low pull. But turning it into a more dynamic movement seems like it would be beneficial.