To be honest I was rather sceptic about this notion that there can be a stiff and supple tire. I thought that this is mostly the matter of a right air pressure. But to be sure I bought a pair of Soma Cazadero 42c tire and compared it to my Panaracer Gravelking Sk 700x43c. As it turned out supple tire is not a myth or hype but a very real thing! Now I use Cazadero on a daily basis and wait for a 650b 50 mm variant to put it on my 650b wheels. That is also why I look for other supple and even wider than 50 mm tires to improve overall riding comfort even more. If you are interested in finding how much more comfortable is a supple tire just read my review:
https://gravelbikes.cc/tests/how-much-more-comfort-can-you-get-from-a-supple-tire/ 