not moved since last year! it should be moved even a few inches every couple of weeks or so! the tyres will have flat spots and stressed, I would say get them changed now as they are coming to the end of their shelf life anyway (5 yrs) but once on the new site to remove them and have the van on axle stands
Moved every couple of weeks! I don't move mine when out and about, just done a 38 day stint and the tyres were absolutely fine, no flat spots. I'm no expert on tyres though.
I know that moving it is the ideal but not realistic when it's on a seasonal pitch with awning up. I couldn't be bothered plus the intention was for it to stay on one site (current circumstances dictate otherwise but we'd have never moved it if we could have stated where we were)