Oxfordshire, United Kingdom

Is it too late in the year to make a few more pruning cuts to a plum tree? It is Sunday today and the weather forecast for my area is dry and sunny till Wednesday afternoon, when there will be some light rain. I am thinking of Silver Leaf Disease. I do not know anything about it, and I do not know if the tree has ever had it.
I pruned it in early August; I did not have time to prune it right in the middle of summer.
There are still a few small branches from this year's growth, growing in the wrong direction, or conflicting with other branches.
There is a branch almost two inches thick with a little damage (sometimes it is hard to tell), but I feel it would be drastic to cut this off now. I have already cut off about a third of the tree.
There are some upward growing ones which I think all want to be 'leaders', and I think I should cut one of these off.
Finally, are the branches that grow at an angle of about 45° the best, in terms of fruit?
Thank you for any advice.

• 25 Aug, 2019