Evidence that Macros Do NOT Cause GCD Delay or Lost Casts

[GrizzlyTank]

Macros queue if you write them to queue. All the details of how that works are in the first post.

Macros have a different type of queue.

When you use abilities you can use an ability and then there is a period where the input for the 2nd ability will queue and trigger when possible.
With macros this is not the case. If you put the same abilities in two macros, when you use one ability, you have to spam the button for the other until it triggers. Since macros don't queue.