I have been using double blocks there for years, even triple in order to have a balanced distribution.
When you use a double block, you may want to look out for a block with an asymmetric or horizontally adjustable shackle so you can adjust the balance there. I never had any noticeable friction or wear from using a horizontal block up there. But do not oversize it, the weight up there matters.
BTW I did not know they recommend a big violin block up there, and even recommend the jib halyard to go over the main wheel, I find that surprising.