Hi @nickharambee,
Thanks for reaching out to us here. We are aware of a performance limitations when using tags that are applied to a large number of tracks.
We have a ticket regarding this behavior and we are looking at improving the performance of these queries, but at the present time I can’t comment on when exactly it will reach the dev queue.
I understand that this is an area that is important to you, and I wish I had better news here but this is currently expected behavior when performing complex tag queries.