Andrew,
Why would black foam be better?
Black is black and it will create thermal and dew problems - but if you are having good results with it without dew issues, good on ya!
By the look of things dew may not be a problem for you - you lucky bugger!
I had not seen your photos before placing this post, so I'm altering it.
Look to use materials and colours that will give you the best result you can achieve. I use Coreflute because I find it practical for me. Yes it costs a bit more than other stuff, but cost should not be the prime motivator. Not to say that more expensive materials are better - they certainly will not be in this niche application. All manner of materials will be possible to use. It's about being creative and resourceful, but also understanding a little about what it is that one is trying to achieve, a little about materials science, and a little about thermodynamics.
Look to avoid Black though. This goes for black OTAs regardless of make or design. A black OTA will always be a dew & frost magnet before any other colour. You may be able to count on one hand all the professional scopes that are painted black, and have fingers to spare. You only see amatuer scopes painted black.
Andrew, if you do find your scope and dewsheild dewing up, you will now know one thing you will be able to tackle to improve things.
That most foams come in black means WE need to look for materials that are white or silver - if the material has black foam filling is of no consequence. Just at least not the outside face of the wrap. Like I said earlier, if dew has not been a problem for you, you are most fortunate.
Yes, SCTs have thinner walls and corrector. What that quote says is just fine in saying an SCT needs even more consideration than a Mak. What is the prime motivation regardless of Mak or SCT, mass production or small batch, it is to slow down the heat loss as much as practical. No confusion to be had. In reality it makes no difference to have "thicker" stuff for an SCT - the same stuff will also work with a Mak.
It is all just about slowing the rate of cooling. If the tube is not allowed to get cold, you eliminate a heat differential being created inside the OTA between the cold tube and warm primary and baffle, which means tube currents are also stopped from being generated from the warm primary and baffle.
Alex.