[Orgmode] magit, revert, folding, normal-mode, performance

[Samuel Wales]

Worth knowing that magit reverts buffers.  It appears to
revert all buffers, not just those with changes.  This has 2
consequences for org.  Magit is slow, and org visibility is
reset to default.

So I wonder:

Is there a way to preserve visibilty across revert-buffer?
Has anybody profiled loading a large org file?

Thanks.