Have you ever considered PICU?
NICU, while definitely being a critical care environment, also tends to be a lot of the same from day-to-day. They almost are all preemies, they almost all have feeding issues, they almost all have lung issues. Sure, there are more specific diagnoses like CHD, CDH, renal anomalies, genetic syndromes, etc. But overall, its a lot of just helping them survive preemie-hood. Assess, change diaper, feed, don't touch in between.
In PICU, you will get babies, kids, teens, even some young adults (for instance, a 20 year old with CF or other chronic disease who is still treated by peds doctors for whatever diagnosis). You will see respiratory disease, infections, oncology, neurological disorders, overdoses, trauma, and everything else in between. Depending on the acuity of the unit, you will see lots of sedation and vasoactive gtts, vents, oscillators, VADs, ECMO, renal replacement therapies, etc. It might give you that mix of seeing both young patients and older patients, and also giving you more variety to prevent feelings of monotony.
Narrowing your search to only day shift positions can limit the opportunities available, but I get it. You could also look for float staff positions at pediatric hospitals - some even have float pools specific for the critical care units, so you would get to do NICU and PICU and really get a lot of variety.