Finishing the first leg
Over the past two sessions I finished off the second mortise on the first leg, taking plenty of time and a lot of care to keep my cuts as close to vertical as I could manage.
The holes still did not meet perfectly in the middle, but it was much better than the first mortise. There was only a 1-2mm deviation.
I’m confident that with just a little bit of smoothing down the sides of the mortise, a tenon should be able to pass through snugly.
In the Paul Sellers videos, he cuts all eight of his leg mortises before he moves on to cutting the rail tenons, but I’m thinking I will cut one more leg and then cut the rails to make one complete leg frame, before I move on to the final two legs. That way, if I have to learn any lessons during the frame assembly, I can benefit from those lessons on the second frame.