Just as I guessed, there are many ways to "skin a cat" and the same applies to this Topic, sorry cat owners.
Even if there was a significant amount of wear involved I would still heel-&-toe regardless. Its part of the whole driving experience to me that is satisfying. I am not hard on my clutches as the last one that was replaced was on my Integra GS-R. I drove that car very hard through every gear change, when the clutch was replaced the mechanic said that the surface was in excellent shape. In fact he asked if I was a "gentle" driver as the surface had a lot of life left in it, the reason for the replacement was because of the a bad bearing BTW.
I was always taught through reading and my Father that it is safer to always be in a gear when moving, for instance if you are braking and coasting out of gear at the same time and then a hazardous situation suddenly appears, you no longer have the instant "power on" option without selecting the gear with a shift change.
I think Jackie Steward also advocates always being in gear before entering any corner, otherwise you will disturb the suspension with a gear selection, I imagine this to be more important at race speeds as you are at the limit already.
Of course, every Heel-&-Toe shift I am referring to also means proper rpm matching, otherwise its not Heel-&-Toe to me, its just plain sloppy.