Restrictions for check in check out and stays
Yes supported, but under "Restrictions for check ins check outs and/or stays > Restrict period" the only supported setting is the box "Stays not allowed including check in". Always be sure to tick this box as the box "check in not allowed" and check out not allowed are not transfered to sales channels like Booking.com, Expedia or Hostelworld.
Please note that restrictions set for a room type are not applied for any duplicate (alias) room type connected to it.
The restriction under "Settings > Restrictions > Bookable days" is supported for Booking.com and Expedia but not the other sales channels. For Agoda, it can be sent manually together with the price update.
Block of a unit or room
You can block a unit by clicking on the unit and choose "block period" It is reflected in Booking.com.
Restricting how far in advance bookings can be made
This setting has to be made on each channel.