All the experienced vMA runs and builds I've seen make full use of the fixed spawn locations of each wave. And that majorly contributes to the improvement in completion time.
So here's a question - suppose the spawn locations in each wave were random. Let the type and number of ads be exactly the same. Just that you can't predict where each will spawn in advance. Would you change your vMA build in any way?
I'm asking in order to see which aspects of builds rely on knowing precisely where danger is coming from in advance, vs those parts of the build that are more "general purpose" and thus suited to someone who doesn't know everything in advance.