This is especially true if you expect most of your future customers to be outside the US.
In the long run this gives an operating advantage to foreign corporations -- again for tax efficiency only.
In the intermediate time frame all governments change their laws all the time, and there are going to be changes in tax rules coming that will make cross-border SaaS sales painful for tax load and administrative burdens, for instance.
Your choice is when to flip your business from US to foreign status. You can see the government attacking late-stage inversions because that is where the revenue and political brownie points are.
This tells you that early-stage migrations are still possible and may be cost-effective for you. At some level, for small companies, practical considerations can be used to offset unfavorable tax rules. (Translation - amounts are small enough to not matter, or be swamped by normal expenses so that they don't matter).
The US tax system is King Canute.
Source: I am an international tax lawyer in my real life.