Someone early on asked what we can do.... whilst it's not tangible, if the school is doing it right, tell them, let the office know that it's good, it's working, that it's appreciated. Honestly, it's such hard work in education right now, that positive feedback really really will make a difference to those it references.
Trust the school to do what they need to do, if you have helpful suggestions let them know (we had issues with lunches and pta funded benches because someone suggested it to help) otherwise keep your kids head down and up to date with work and support them as much as you can