If anyone happen to ever had USCIS's legacy account, I suggest they keep it active or restore their access to it and add their N400 case there. I have been testing and noted that alerts of case events appeare to be far more accurate and in real-time. Though it lacks features such as access to PDF notices etc, its notification capability is phenomenal. Forexample, as soon as I finsihed my interview and finished the checklist of Oath on a tab, I had received an sms that "We recommended that your Form N400; Application for Naturalization be approved."
I feel like it is better than having to keep refreshing myuscis account.
https://egov.uscis.gov