I cannot see any way such a receiver will blow out an LNB on a regular Chaparral feedhorn (if that is what you're talking about). But, the AZbox won't control the polarity servo on the feedhorn, so that's a big negative.
In a related use, when you have dual LNBs for each band, as on an orthomode feedhorn, connecting that to a traditional DVB receiver which wants to select polarity with 13/18 volts, you would use a multiswitch. Pendragon described a mod to a common multiswitch, which supplies 18 volts to both C-band LNBs.
i have had standard lnb's run just fine even on 13v after a 150' run of RG-6. I know the cheapo bsc-211's don't care what volts they get. I have heard that the norsats can be erratic on the lower voltage.
I ran a standard directv multiswitch for about 3 years on my big dish with an ortho feedhorn which gave my horizontal c and ku lnbs 18v and it gave the other two only 13v. i had no issues.
you can go with a 22k switch. The only time you cant is with a Universal LNB (the UNiversal has a 22k switch built in) They arent that much more...I bought some ecoda switches off ebay for under 10 bucks shipped. They work great