You would want to avoid using any words like "grandiloquent."
A good rule of thumb is if you really have to think about how to use a big word, spend that time thinking of a simpler one to use in its stead. The key to SOPs is clarity and precision, not fancy vocabulary. Remember your audience: these are professors who, yes, should understand all these big words, but have to read through possibly hundreds of statements and will very much appreciate something clear and precise over something wordy and flowery.