I think this is a reasonable answer and may be all you need considering the Moxon is fairly widebanded.If you were really worried about it breaking I suppose you could slide some PVC over the joints to add some rigidity to them. Personally I would just tune it for the low end of 10 and go with it there. The SWR would still be in the 2.0 and under range which is fine.
alternate method would be to leave it set for 10 meters and load the elements down to 11 meters with a wire tail mounted at each corner make the tail a little longer than required and trim down for VSWR.
read this article https://antjab.wordpress.com/2012/06/07/even-simpler-moxon-tuning/ great idea takes the pain out of tuning any moxon.
I forgot about the tail idea. Should be very easy to do.
I used the Moxon Generator app that Tba02 looks to have used when I built my Moxons.