A99 flash delay?
There is this other thread in another forum:
Below Friedman's blog there were also some comments.
Basically you will have the same delay using HVL F60M as wireless trigger as well.
Someone mention F20AM triggering older F56AM has no delay but I gave that flash to my son so I cannot verify.
I did find that by engaging FEL lock (c button top front left) you get no wireless TTL flash delay. That button is set to toggle by default I think so you have no delay until you unlock FEL by pressing button again or by play to review image. Whether that is a good enough work around for you only you can decide.