Resident in Luxembourg - Feedback on banking and card setup?

Hello,

I recently moved to Luxembourg and I'm looking to optimize my banking and card configuration for interest and rewards. Here is what I’m currently :

Primary Bank: Spuerkeess. Have this already.

Main Card: AMEX (French version) for daily transactions to earn points. Have this one too and linked to spuerkees.

Savings/Investment: Trading 212 for the 2.2% daily interest on cash and ETF investing. Scouting for better options

Backup: Revolut for RevPoints and for when AMEX isn't accepted and preferably some lounge access. Scouting for something better here too.

I’m looking for suggestions to improve this:

1. Does anyone have a setup that yields better than 2.2% on cash while remaining flexible?

2. Has anyone found a better card combination (e.g., using Curve) to stack cashback or rewards more effectively in Lux?

3. Is it worth the upgrade to amex platinum or revolut metal or something given their high fees.