Can we move on to other toys or levels before we’ve mastered the previous ones?
Mastering a toy is definitely not required in order to move on to the next one...or even the next level. Exposing your little one to the toy and allowing time to explore it and experience it with their senses is most important. If it’s time to introduce the next toy and you notice your little one is ready for more variety (without mastery), go for it! If they are content to continue to work with the toy and try to master those skills, then wait a few days. The timeline is a suggestion, and no one knows your baby better than you do. Observing and moving forward or pausing as needed at any point is perfectly acceptable.