Changing Photo to Avoid Medical

So, just under 5 years ago I renewed the photo on my licence to extend it for up to another 5 years without the need to have the medical at 50.
Well that extension has just come to an end at midnight yesterday the 3rd of June, which just happens to be the day before I passed my class 1 test in 1988, is this just a coincidence? or did any others who did the same thing get an expiry date the day before they past their test?
Since I am doing other things at the moment, I’m going to wait until I reach 55 in September to take the medical so I get the full 5 years next time.
And like most my driver CPC also expires in september, would it be ok to take CPC courses between now and September whilst i’m not legally licenced to drive a class 1 until I’ve renewed it?