Interesting Update:
By invitation, I sent the EMP S4/1PCT-W2 cascadable switch and one of the BEST switches back to EMP in the Czech Republic for investigation as to what the problems might be, and here was their answer:
"Good morning John
after more testing, we can confirm your results. The "Best" switch is working fine if connected directly to the receiver, but it does not understand the commands which are generated by our S4/1PCT-W2 switch. In fact, it does not respond properly to any of our DiSEqC generators, neither standalone nor built within S4/1PCT-W2.
It is the first confirmed incompatibility case of our DiSEqC generators. According to our manager, our response now should be to recommend to use our components for systems with S4/1PCT-W2.
Based on above, there are following working solutions for you:
1/ Use your S4/1PCT-W2 switch in connection with other EMP-Centauri DiSEqC components, e.g. S4/1PCN-W1 (confirmed to work)
2/ Use "BEST" switch with our other model, S4/1PCT-11 universal multimode switch
http://www.emp-centauri.cz/index.php?lang=en&page=prodview&id_kateg=1&id_pkateg=17&id=281
This combination is confirmed to work as well, for this switch does not generate new DiSEqC commands, it just passes through commands incoming from receiver."
Thus, the BEST switches appear OK for standalone use, but don't appear to work in any cascadable set-up !"
Wonder if any of the other widely-sold switches have the same issue?
NB: My reply to EMP was that I think I have a stable system with the 10-way switch at the moment, and, also - having lots of other things that I need to do right now (like the problems of upgrading W7 PCS to W10) I don’t propose to make any further changes to the satellite systems dishes setups at the moment.