@JackCoopersmith , thanks for the response! This is wonderful news! I can suggest a few basic features that would be a bridge between Hubspot and a full blown reservation system. In order of importance:
- The ability for customer to increase the unit amount of product
- Cart function to allow customers to buy more than one product at a time
- Add discount code option in the customer-facing payments page
- Ability to collect custom property fields in the payments page when you want to collect more than billing info (right now it is a two-part workflow… fill out the form then get redirected to payment link or the other way around). Especially for an “I agree to the terms” check box… or a signature check box, like with quotes.
- Add all quotes paid to the payments activity log
Thanks for asking for feedback 
I hope this is helpful!!