The +10 clause means on-site guests (or select hotels with the +10 benefit) who checkin a day before you and book 5 nights (as an example) already took the first 4 days of reservations (60+4 of your window) and so all popular restaurants will be booked. Usually you can get some reservations on the 5th night and Oga’s/Space 6th/7th night.
If staying offsite and you don’t have the +10 benefit, you can only book a day at a time and will have little to no availability for the most popular ADRs.
You could sign up for Touring plans Disney dining reservation finder (or something similar) and get text alerts but have to be quick and reset each time it finds something.
https://www.*****************.com/blog/ins-outs-disneys-advance-dining-reservation-system/
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