QK - I think good snap-caps - the more expensive ones with a good cushy insert where primer goes - are worth using. I know most modern guns permit dry fire with little or no prob but always seems to me kinder to let firing pin impact - something.
Other point too - I have some 38sp dummies and these are great for speedload practice.
One more use too - get a buddy to load your mag - ''ball and dummy'' and check your shooting stability and flinch - or not - most useful.
So - worth IMO having certainly a half dozen of the main cals in snap-caps.