Ill answer, because I have swapped out dials on many watches, and more than a few ETA 2824 movements.
Short answer is :No it wont fit .5mm does make a difference if your measurements are exact as to how much room is in the watch case. If you are guesstimating or getting approximate measurements, then THAT is your answer.
.5mm is a HUGE difference in space when it comes to a watch.
But I HAVE also shaved watch dials to fit watch cases they werent meant to fit in. .5 mm is easy to shave if you have patience and the right tools. I use a dremel tool with rotary sanding drums that are a little used, so they dont remove materials quite so aggressively .Then I use 800 grit sand paper to clean up the edges. I just grind a little off the outer edges, using my fingers to twist and advance the dial. You wont get a precise edge, but it will be close if you work slow and careful .
After you are done, use Rodico putty and dab the dial clean.