You can always decline any collaboration inquiries or reservation requests that you can’t facilitate, but you should do so within 24 hours. Whether you accept or decline, the amount of time it takes you to respond to requests is factored into your reviews. Rejecting a large number of requests can have an impact on your profile ratings.
When you decline a reservation request, you can choose to keep the calendar dates blocked or make them available for someone else to book. Update your calendar regularly so you’ll only receive reservation requests for when you’re able to join in the ecosystem.