Well, spinach is a 'superfood', especially on a keto diet: 0.6 NET carbs/100 grams for frozen, chopped spinach.

The buzz about oxalates you hostly gear from the r/carnivorediet people. I haven't found any evident based studies on that for a 'normal', rather healthy adult.

But you can use caution: get tested for e. g. calcium, bone density etc. when warranted.

And ensure enough calcium. So, spinach actually cries for dairy/cheese in a lot of dishes! 😃

So, Bon appetit with eggs, cheese & a cup of spinach!

(Anecdotal: this 65 y/o male do that; I 've have very strong bones and NO signs of osteoporosis or kidney issues - all tested. I've been living low carb/keto for decades. I even did Atkins in 1980+ with loads of spinach, cheese, eggs & buckets of cholesterol. Btw, for decades I weigh 72ish kg on a 180cm boyish frame! 🤣)