Should I make Reserved Instance (RI) purchases or exchanges outside of ProsperOps when it is enabled?

While we can't prevent that, it is strongly discouraged. ProsperOps algorithms will automatically build and maintain an optimal RI portfolio, so outside RI changes are unnecessary. If RI changes are made outside of ProsperOps, the algorithms will discover those changes, log them, and adapt the portfolio, but your savings rate may be negatively impacted.