Had a first go with two ropes today, so limited tries so far I know. but overall I'd say it was pretty positive.
It was slower yes, but i'm not practiced with it so this will speed up, and it wasn't that slow anyway.
I used the following method, which I'm going to try and refine some more to see how it goes. as an idea the tree was perhaps 18m high and a Sycamore, so usually a fair amount of solid points to use as anchors.
1 Main line, SRT set up as usual.
2nd shorter line, DRT (could also be SRT to get extra length out of it, but more moving to retrieve it each time) today was a 5m line, I have a 15m one also If needed. (Also one of the points in the original post was about space on the ground and extra ropes etc, This second line doesn't need to reach the ground mitigating that problem)
3rd short line 2.5m I think.
This works as this article, in the FAQ bit, states only 1 has to be long enough to reach the ground uninterrupted...hope its not that one that gets cut!
I used the 2nd shorter line as my 2nd Anchor always around something that could take my weight fully on its own, in case the main line/anchor failed.
and used the 3rd short line to strop in, also always on something that could take my weight, whilst moving the 2nd anchor point around the tree.
Then whilst cutting I had 2 points of attachment, on independent anchors, 1 long enough to get to the ground and a 3rd and to hold me in place as usual.
So rather than look for 2 anchors to set up and leave for the duration of the job, I moved the second anchor around with me. I think it worked pretty well. Takes a bit more forward thinking to plan a second line as well as the main line. But on this tree is was more than possible to implement it.
As said only tried it on one tree so far and I'm sure there will be times it will be annoying.
But today was fully compliant and easy to implement and work with.