I guess it depends on your customer model, but surely the keyword there is "begin"?
It all depends on your customer/business model. If you're expecting to get to 1000s of clients quickly (i.e. within 12 months), then this will be an ops nightmare, unless you have really good automation.
AFAIK, historically that hasn't happened. Sales is shit hard. Getting every single client is an art in itself. You got to be a magician to get even 5-10 clients signed-up readily in one go, for a start-up. And by the time you are having "N" paying clients that matches your metric for product-market fitness, you start evolving your architecture to the next level. This is where Product and Engineering sit-together to take that strategic decision on the path forward.
> Suitability: This is the best way to begin your SAAS platform, for product-market fitment until stability and growth.
Uh what? How is this even feasible when you get to 1000s of clients?