Currently, we have Four SLOTS (Resources) ... These Slots are available daily, in blocks of 1.5 hours, max.
CURRENT SCENARIO
Users Can book Only 1 SLOT per day (This is working, as intended)
Users are limited to booking only 1 resource per reservation (This is working, as intended)
Users are limited to only 3 reservations per week (This is working, as intended)
In the Schedule -> Booking , the user can make multiple single SLOTs reservations, spread across several days into the future (This is something we want to prevent
WHAT WE WANT
A User should be able to make ONLY 1 reservation of 1 Single Resource (Slot), at a time. So, FOR EXAMPLE : If a user makes a reservation for the 21st September 2020, he/she should not be able to make another reservation, before that date (unless he cancels the one for 21st September 2020), nor should he able to make another advance reservation, for after 21st September 2020. ONLY once the booking for the 21st September is FULFILLED (CONSUMED), can he/she make another reservation..
Set a quota to limit the amount of reservations per day + week + (maybe) month (in your case it looks like only setting a "day" rule won't be enough)
If you want to prevent your users from booking to far ahead, that can be done easily in "Resources", using the field "Reservations must not end more than X days from the current time"
A User should be able to make ONLY 1 reservation of 1 Single Resource (Slot), at a time. So, FOR EXAMPLE : If a user makes a reservation for the 21st September 2020, he/she should not be able to make another reservation, before that date (unless he cancels the one for 21st September 2020), nor should he able to make another advance reservation, for after 21st September 2020. ONLY once the booking for the 21st September is FULFILLED (CONSUMED), can he/she make another reservation..
This is not something out-of-the-box from Booked - though not difficult in a plugin (in fact, we have done just this as part of a plugin for another client). We'd be happy to discuss breaking out this particular feature into a custom plugin for you. Contact me if interested - https://Apps-n-Add-Ons.com/contact.php