SBLOC as source for equity injections

Let's discuss the viability, pros/cons, and risks of an SBLOC to source funds to make equity injections to take minority stakes in businesses. Example, $500k SBLOC that can draw down 5 tranches at $100k each. Preferred returns of 25-30% more than cover the interest on SBLOC such that principal can be repaid in under 5 years. Yes, this assumes no margin call on collaterilization of the SBLOC and assumes rates remains constant. But for example purposes.