Another Bi-wiring question: Amp related

While experimenting with different bi-wiring arrangements between my McIntosh MC2200 and Vandersteen 2Ci speakers, I’ve concluded that using the 8 ohm tap for high/mid and the 4 ohm tap for low (bass) gives the best sound. Nothing real dramatic but audible to me. It probably has to do with the different damping factors (output impedance) for the two different taps along with my fairly long speaker cable runs. Anyway, my question is, 1) has anyone else tried this approach on their amps, regardless of the brand, and 2) would this approach harm the amplifiers in anyway. I suspect the answer is no for the second question but just curious and wanted to ask.
Thanks.