Senior Mobile Architect Consultation — Flutter vs React Native

Overview
 I am looking for a senior mobile developer to give me a direct, experienced opinion on the best stack for my new iOS and Android app. This is a short paid consultation — not a full project. I need a real answer from someone who has actually shipped apps, not a generic comparison anyone can Google.
About the App
 A virtual pet wellness app for iOS and Android. Users complete daily mood check-ins and wellness habits. A virtual cat reacts to their consistency through animations and mood states. The app includes subscription billing and targets both the App Store and Google Play from a single codebase.
What I Need From You
 A short written response covering:

Your stack recommendation — Flutter or React Native, pick one
Three clear reasons why it suits this app
One honest risk or trade-off I should know about
A high-level architecture suggestion for the chosen stack
No lengthy report. No copy-paste comparisons. Just your real opinion based on experience.
Required Experience

7+ years in mobile development
Have shipped at least one Flutter or React Native app to the App Store or Google Play
Strong understanding of native iOS (Swift / Objective-C) and Android development
Experience with subscription billing (RevenueCat preferred)
Can give a direct recommendation, not a both-are-good non-answer
Application Requirements
 Please include the following or your proposal will not be considered:

One app you have shipped and the stack it used
Your one-line opinion on Flutter vs React Native right now in 2025
Your fixed price within budget
Your availability and turnaround time
Deliverables

Stack recommendation with three reasons
One trade-off or risk to be aware of
High-level architecture direction for the chosen stack
Delivered as a short written response within 1–2 day