If you have a scatt, it's a good idea to use it but beginners oftentimes don't have one. It also depends on the goal you have for your training. If your goal is to only focus on your inner position and just feel the position for example, the scatt does not bring you any added value. But if you want to focus on your target times, scatt could help you to observe it better in an objective kind of way.
Is this type dry firing training recommended with scatt or without scatt ?
If you have a scatt, it's a good idea to use it but beginners oftentimes don't have one. It also depends on the goal you have for your training. If your goal is to only focus on your inner position and just feel the position for example, the scatt does not bring you any added value. But if you want to focus on your target times, scatt could help you to observe it better in an objective kind of way.