It would essentially be the same thing, just achieved differently and taking a little more time (to find the mindshrooms and then the cave in which to do them in) - it just would allow another option! I think it'd be very cool, and would forgo the immediate ability to have psi powers for being able to do it this alternate method that for RP purposes could be fun.
Maybe they could do something more with it like reveal more lore about psi abilities/history to some degree to have a payoff for choosing the "longer method", but I'd be happy with no differences other than the time+choice in the matter.
I hate taking pills (well, I actually don't ever take any pills, personally), and find the "immediate gratification" method not to my liking.