Are you asking if it’s ok to eat only 500-700 calories a day for 5 out of the 7 days of the week? No. Adjust your eating window so you’re hungry at your break time, or do OMAD and eat one 1500 calorie meal when you get home.
Honestly it’s kind of impossible to do IF and intuitive eating at the same time, because intuitive eating is about eating when you’re hungry, and IF is about limiting when you can eat. They’re at odds with each other. At a certain point you do need to actually make sure you’re getting enough calories! And if you’re committed to doing IF then that might mean eating when you’re “not hungry”.
You could officially switch to OMAD and make your dinner a larger meal (1200-1500 calories). It sounds like you are basically doing OMAD right now anyway — just eating way too small of a meal. If you know that will be your only meal of the day anyway, why do you not want to eat more than 500-700 calories at that meal? It’s not like you need to save the calories for another meal.