I think it would be awesome to have a mysterious recurring character through a doctors final season maybe bringing a warning or an urgent message from the future and then at the end of the season the doctor regenerated into them
Instead of falling out of the friggin Tardis to Earth and somehow surviving like "Superman" due to the power of regeneration, yes this is far more acceptable. Even if everything went to the shits afterwards in regards to the series overall. Yes this introduction would've been far more sensible much agreed!
If that had really happened it would have been a total ' drop me bacon buttie moment!'. " Wilfred, you've been staring at the telly for the last five hours now-stop it!"😁
Gives me some kind of Devious vibe, where Pertwee showed up to fuse with the Second and half Doctor (here played NOT by Jo Martin) in order to get a proper regeneration.