My H1b Visa expires in Aug 2023. I believe I cannot apply for an extension until Feb 2023. My prior H1b stamp on my passport had expired back in 2017. Due to the recent difficulties finding appointments for H1b stamping, I was looking in Mexico City and I was able to find one in Mexico City in early Jan 2023. Is it safe to go for stamping 6 months prior to I 797 expiration?