I believe it is best to leave this to the watchmaker. Tightening a case-back and ensuring the watch leaves up to the specified depth needs more than screwing it back on. Seals and testings is a must. If you do not dive then you can tightened it back relying on hand force.
For me it's a triple A. A1 for style (with a real bronze case with a great patina effect, bronze buckle and bronze keepers) A2 for build quality (including known reliable movement) A3 being I'm sensitive to it, it's Italian and moreover made by someone special for me The WPS2021 for me ticks all the