I don't know if browsers are capable of doing the flash reliably. I tried it out (non-epileptic and curious), and you can see that it's not a reliable 40Hz flash on either Chrome or Firefox.
I haven't looked to see what technique you are using for the timing, but there's quite a bit of jitter.
EDIT: it's using requestAnimationFrame.
Rather than using that, have you tried using CSS keyframes? They may have a more privileged timer, and they'll be immune to GC.
I don't know if browsers are capable of doing the flash reliably. I tried it out (non-epileptic and curious), and you can see that it's not a reliable 40Hz flash on either Chrome or Firefox.
I haven't looked to see what technique you are using for the timing, but there's quite a bit of jitter.
EDIT: it's using requestAnimationFrame.
Rather than using that, have you tried using CSS keyframes? They may have a more privileged timer, and they'll be immune to GC.