I suppose technically, you are right. You'll only get the nymph while mining so just staying in one spot will maximize the process. But, you spend very little time running to the next blockage, compared to the amount of time you spend mining. If you choose to mine on the themed world, than you won't even have to find the blockage yourself, you just have to simply follow the crowd.
It might also make the time there go faster by following the crowd. It breaks up the mahogany of just mining in one spot for hours. Not to mention, it can give you a chance to be social with the other people there too.
You'll get the mining suit either way, I'm sure. But I think you'll find a better experience following the crowd (you'll hear stories of people with far worse luck than you with the suit, took me over four hours for my second item) and might as well boost your experience a bit while doing it.