it's not a smaller envelope to avoid - it means you can get into VRS easier (ie with lower RoD) in an aircraft with a lower disc loading. You have to have a higher RoD to get into VRS in a helo with a high disc loading.
Hence, smaller and lighter helicopters are more vulnerable to VRS since you can encounter it at lower RoD than in a big, heavy powerful military helo.
no. really??? The graph you are referring to was posted on here many years ago by Nick Lappos - it shows that you need to have a RoD around half to 0.6 of your downwash speed to encounter IVRS and around 0.7 to be in fully developed VRS,
Why are you repeating what I say and then contradicting what I say? And please tell me how the envelope is not larger when I actually presented the numbers from the actual forumla comparing the same helicopter at minmum weight and gross weight. Seriously dude, you have issues.