Actually I do practice these. CESA, I do very slow and more along the lines to see how close to my safety stop I can get, rather than actually making it to the surface. I keep my reg in my mouth the whole way, just exhale. My thinking is that, since I do a lot of photography and I have seen several other photographers get to an OOA situation, that I should just in case I dive someday minus my brain. I do stop at my safety stop and then finish the dive normally. Depending on my 'urge' lets me assess how I did and the changes I would need should it be real.
Most of the time my ascents are from roughly 60 ft, one of the benefits is that since I've done it so many times, it just doesn't phase me, and I'm relaxed. Now whether or not that would translate to being very calm in a real OOA situation, I won't know until it happens, but I take comfort in knowing I could do it. I do try to stay well under the 30'ft min ascent, and I only do it when the viz is good, I told my buddy a head of time and there is at least one other person with my buddy when I do it. I also limit the locations to those where there is no danger of getting lost etc.
As far as ditch and don, I should practice that more, as I've had to do it several times over the past 25 years due to circumstances. One of the reasons I loved the original Black Diamond was it was so easy to D&D underwater. Unfortunately it also responsible for the most real life need to D&D. As I get older it gets a bit more difficult for me to do, and I'm finding myself doing it the PADI way now. While you did not ask, my wife practices surface D&D every dive, as she can not get in or out with gear on due to an injury. It is interesting to see how she can jump in grab her bc get into it, and down before many folks get down after jumping in with their tanks on.
All this said, I don't recommend folks whose skills are not up to date, do this without compentent help there just in case, better still do it in a pool to get your with a buddy skills back.
Bottom line I've had to do D&D several times for real, I have never had an OOA in the ocean but I still train just in case.