grannyring ...
Congrats for figuring out the problem causing the poor performance of your single mat. I’ve suspected for awhile now that some of the previous tweaks being used by a couple of members here have had a detrimental effect on the mats, or at least block the "goodness" of the mats. The improvement afforded by the mats have been so profound in my system, and the systems of my local friends, that I just knew there HAD to be something going on. I sincerely hope others will take heed in what you’ve reported here.
By the way, multiple mats increase the effects you are experiencing with the single mat. Expensive? Yes! Expensive for what they do? No. :-)
Frank