Absolutly not. KH's servers are perfectly capable and compatible with vBSEO. If a customer had an issue, it was related to something with his/her configuration and needs to talk to vBSEO support.
VBSEO is awesome, I have it so since 2months, runs perfectly with my lighttp chroot, you can check my server specs here its the smallest one offered and as you can see it runs very well without overload, well yet my site not opened for visitors but I'm doing tests for now with spider bots and noload behaviours encountered, I like a lot this product since unencrypted, hope you'll appreciate it