Solid or Pop Rivets - 9A Elevator Spar

Working on the right elevator (9A) and the instructions say that the underside of the spar/skin can use pop rivets vs solid rivets. But they do mention that many (but not all) of the rivets can be solid if you have a long enough yoke to reach through the bearing cutouts in the skin. The decision has to be made ahead of time since the holes get drilled different sizes depending on which adventure you choose.

Is there any advantage to using some solid rivets where possible? It's all on the bottom of the elevator, so I'm not sure how often they'll be seen. Although really, it seems like if looks are the issue, a consistent row of pop rivets would look better than half and half anyway.

I lean towards just using the pop rivets, if for no reason than to limit the frustration factor anywhere I can. Any reason not to?

Some Solid, some pull rivets

In my elevators, I did a combo of solids near the bearing cutouts where I could reach with the squeezer, and the rest were pull rivets (I think the MK-319-BS ones).

All solid rivets. I made myself a 'bucking bar' of 3/4" x 2" steel x 66" long with a custom shaped end with polished faces bolted on. This fit through the opening in the elevator. Taped the bar with duct tape to protect the inside of the elevator. Clamped one end of the bucking bar to the workbench. It was pretty easy to index the elevator to each subsequent rivet using the tail of the adjacent cleco. Worked excellent!