The Lafuma looks plush and comfy! I have a good clone but the padding is not as clean as the Lafuma. I wish there was a way to raise the armrests or attach after-market armrests to support elbows and arms for longer and more comfortable viewing.
I understand your want to raise the armrests for longer and more comfortable viewing. My solution, for years, has been to mount my binoculars on a collapsed monopod, Finn-stick style, with the base of the monopod at my belt. This increases the duration with which I can hold the binoculars without reducing where I can point them. It eliminates, for me, the need to raise the armrests.
I should say that I hold the monopod, not the body of the binoculars. The binoculars rest against my eye sockets. My hands are therefore positioned lower down. YMMV.