I believe so. It is my understanding that the NIPs are more agreed upon guidelines and that the clients usage of them is what solidifies the practical standard (correct me if I am wrong). 

I do plan to both experiment and test other clients use of these NIPs and work on building some. 

#NIP15
#NIP88
#NIP99 

 Sounds right to me. Basic messaging protocol (which nostr already is!) is a pretty good foundation for building momentum in a lot of different directions. Once momentum is built it’s probably easier to get consensus about prioritizing work/consensus on NIPs.