Thanks, appreciate your insight!
The part I was referring to as "risk-free" relates to the principal itself. Hypothetically, if I invest $10k of principal into the units post-IPO, I can either generally sell in the open market around the IPO price of $10, or choose to redeem my unit shares for my principal + any accrued interest. So, from that perspective, I believe initial principal you invest in the units are, for lack of a better term, risk-free.