Earlier quoted context omitted.
What will happen if someone tries this?
Taking beta-alanine will increase Carnosine synthase activity and probably lead to a depletion of magnesium and/or manganese since they are the co-factors for the enzyme. So this effect will differ based on genetic and nutrition. https://www.uniprot.org/uniprotkb/A5YM72/entry
Side note: If the aim is to increase carnosine in the body, I'd do carnosine as its better absorbed than beta alanine according to some studies, and then there's the remyelinating effect of histidine on the nervous system amongst other things, which is beneficial for some types of mental acuity, useful if you want to be a stand up comedian or some other verbally quick witted individual.