Leaving Ahmadiyya and Planning My Nikkah

As-salamu alaykum. My dad is a devoted Ahmadi but I left that belief a few years ago. He’s also very set on marrying within Pakistani culture and within Ahmadiyya. My mum technically converted to Ahmadiyya but doesn’t really practice or believe in it. I’ve tried talking to my dad about why I don’t follow it anymore, but he’s so set in his views he won’t listen. My mum advised me to keep quiet until I move out. I want to do my nikkah with a white revert to Islam. My mum and my brothers all know and support me. We’re planning to wait a few months before telling my dad - just until I have my job settled and he has his - so I can move out and not have to live under that pressure. My dad is strict about Ahmadiyya, but in some other matters he can be open if you approach him the right way. My mum will try to persuade him, and my older brother will help too. I spoke with the imam at the Sunni masjid I attend about the situation. He said that because my father is Ahmadi, he would not be considered my wali from a Sunni fiqh perspective, and that refusing the marriage just because my fiancé is white or non-Ahmadi would not be valid reasons to block the nikkah. So, according to that fiqh opinion, I can proceed with the nikkah. It still feels uncomfortable, but I understand that is the legal ruling. This is a pretty specific situation. I was wondering if others have had similar experiences - especially with an Ahmadi parent and questions around wali and nikkah - and how you handled it.