I think "how hard is it?" is the wrong question. We should be asking "how can this be better?". It doesn't take very long to type something like "as far as I know", but we still routinely use acronyms like AFAIK, because as long as everyone knows what it means, it's often a waste of time to type the full thing out. The only difference here is that VSRE is not already a custom.
VSRE doesn't work. It's better to just type out what you want to say in this case.