If you are worried about dropping the smallish ( M6) nuts behind the chuck on mini lathes, Danny M2Z came up with a simple and easy to make a means of holding the nuts whilst a spanner is used to rotate them. Highly recommended.
A scaled up version would be equally useful for larger sizes.
One lathe has a screw on chuck, with dogs, to allow reverse running. I do not use back gear to slacken the chuck. Each chuck has a 8mm hole drilled in it. A long bar with a 8mm round silver steel fixed to the end is inserted in the hole before being given a smart blow with a copper/;hide mallet. (Belts tight, to maximise the inertia ) Works a treat!
The mini has a bolt on chuck.
Howard