Thanks for the tips.This is one of the reasons I gave up on Tannus in my Marathon+ tires. The other was, they compress over time and loose 70% of their thickness, unless you deflate the tire when you're not riding.
To install the Tannus, I used tire talc and lots of rim lube with very little air in the tube. I also used these heavy duty tire levers:
View attachment 209026
Use caution with these. It is possible to apply enough force to deform the rim, or even break the tire bead wire.
I have since switched to Mr. Tuffy liners and Muc-Off sealant. I also use Schwalbe heavy duty downhill tubes with the Marathon+ tires.
The ride is still a bit stiff, but much less so than the Tannus. I reduce the tire pressure a bit to compensate.
Interestingly, I received an email response from Tannus Amour America advising me that they do not make a Tannus Armour for the Schwalbe Marathon Plus with it and my wheel combination, i.e. 700x50c or 28x2, which I find odd in that there is a YouTube video published by Electric Avenue showing them installing one on the rear wheel of the Gazelle C380+ on the original Marathon Energizer Plus tire.
However, no point in prolonging a lost cause so, on to plan B.