(on the assumption that there are assets)Will short-term promissory notes make settlement smoother?
Bitcoin transactions are "settled" (confirmed) every 10 minutes on average, and if there is a transaction with a sufficiently high fee attached, it will settle (confirm) the next time bitcoin transactions are settled (a new block is found).
Any debt transaction will almost certainly take longer for you to have access to your money.
As a side note, there are many debt transactions that take place for reasons unrelated to the type of money being transacted. For example, some merchants will receive inventory from a vendor, and will finance the payment for said inventory via a lender with a maturity of when the inventory is expected to sell. Merchants use these types of debt facilities because they do not have the money to pay for their inventory up front, and is typically slower than a hypothetical situation in which the merchant was able to pay for the inventory up front.
The above is not explicitly what you are asking about, but your question reminded me of the above situation.