I’ve done things similar to this as a purchasing manager (in a different industry). Providers sometimes required a payment schedule that was critical to their cashflow (and I did feel very sympathetic), but I had to pressure them into a very unfavorable schedule - otherwise the contract would never be approved by finance. Small companies sometimes had hard time understanding that there were rules I simply couldn’t bend, and it was rather unpleasant at times.

However, that was always sorted out during negotiations.