Help! Company wants to go cross platform. Flutter or KMP ?

The existing app is in natives, iOS(Obj C) and Android (XML based). Wifi and Bluetooth Connectivity with devices functionality is also there.

We are one iOS dev(~7yoe) and one Android dev. I on the Android side (~2 yoe, native android exp, react native secondary skill)

The iOS dev is in notice period and is interviewing for this replacement(again, iOS dev). He is pushing for Flutter since he is learning it for two months. I have no exp with it. Proper rewrite (mind it, the app is large and has many screens and activities).

I am pushing for KMP since only UI needs to be different, business logic intact in kotlin. So, incremental works.

The decision needs to be taken by both of us. Not able to understand what to do. Please suggest.