What are you talking about???
Legacy receivers can read ProPlus switches (like the DPP33 switch) without DP adapters. Also you are just asking for unnecessary trouble if you use an integrated switch/LNB if you don't have to, your better off using 3 DP duals.
Re-read my previous post, "It depends what sat. your locals come from. If you need 61.5 for your locals you still need 129 or 72.7 to get all of your locals."
I meant to say if you need 61.5 for your locals you still need 129 or 72.7 to get all of your HD.
However, if you are referring to cascading.
Cascading is for legacy switches. Trunking is for DP and some DPP switches. You would cascade two SW64 switches by running splitters off the duals. One side of the splitter would go to 1A on the first switch and the second side of the splitter would go 1A on the second switch. You would continue this pattern for the remaining duals (could also be done with a quad and a dual). Lastly you would need to use feed through loads on port all three B ports on the second switch. This simulates a power draw so that the switch works properly. This is how a legacy system would be setup to have more than four receivers in a system. However, as a general rule if the customer had this setup most of us would probably upgrade them to newer equipment.
The rule of legacy receivers in a DPP system is that at least one of the receivers hooked up to the switch or LNB needs to be a DP or DPP receiver. A legacy receiver does not output the same 19 volts that the newer receivers put out which puts the system at a greater risk of failure.
However, I do agree that it might be better to put in three duals. I was just merely giving one working solution. There are countless others. Plus we still need to know what satellite his channels come from to make a final determination for his setup.