Multiple disadvantages, no real advantages.
If one property goes up 10% and the other down 10% – no equity release for you.
If you use lenders mortgage insurance you’re up for significantly higher costs.
Utilising a single lender is a great way to run out of borrowing capacity exponentially faster, by crossing up your initial portfolio you make it difficult to unravel in the future, potentially cutting your investment potential short by as much as 50%.
Upsides: Slightly less paperwork for the person putting the loan through.
I’d much rather unlock the absolute most potential for investing as possible, than be lazy and hand over flexibility and any ability to keep an agile and evolving finance structure.