I am also by no means an experienced one pocket player, but I have been using the SD for several months now on my home table as well as other places. I haven't had an issue yet playing one pocket where thinning a ball off of the stack didn't work out the way I thought it would. I don't play 14.1, so I can't speak from experience there, but I imagine it would be the same. The thing that differentiates the SD from the Magic Rack in these situations is the thickness of the plastic dots. The dots are significantly thinner than the plastic used for the Magic Rack, which is why they don't affect the roll of the balls as much.
I played in the Swanee a few weeks ago, and I saw my opponents miss two balls that were sitting on the Magic Rack when they shot at them. They missed because they skidded a little bit right after contact. I have yet to see that happen with the dots, and I can only conclude it is because of the thickness, combined with the fact that the dots adhere to the table, while the Magic Rack is loose. Please don't take this as me bad mouthing the Magic Rack, because I think it is a great product, and I used it prior to getting the Slug Doctor. It's just that now that I have the Slug Doctor, I don't need to use Magic Rack anymore.
The dots used with the Slug Doctor only hold the balls in place if you get them dead center in the hole, which isn't hard after you've used the template to fix them to the table. You can actually sit a ball on the edge of a dot and not have it roll in. I think this is why it works well for one pocket. The balls do start out frozen, but small adjustments to the stack are possible with thin hits. The stack does not explode, unless you hit it too full.
Johnny