nRF54L15 proprietary mode: Custom 250 kbps FSK configuration for legacy device (non-nordic) compatibility

[dp]

I'm developing a solution using nrF54L15 that needs to receive packets from existing legacy RF devices in the field that cannot be modified.

Required RF Parameters:

• Modulation: 2-FSK
• Data rate: 250 kbps

My Research So Far:

• nRF54L15 supports "proprietary 2.4 GHz protocols" with documented rates of 1M/2M/4M bps
• IEEE 802.15.4 mode uses 250 kbps but with O-QPSK (not FSK)
• Bluetooth LE modes use GFSK but at different rates (125k/500k/1M/2M bps)

Questions:

1. Can the nRF54L15's radio peripheral be configured for 250 kbps FSK modulation in proprietary mode or any custom mode available?
2. Are frequency deviation and channel spacing parameters configurable for custom applications?
3. Are there low-level register configurations that might enable custom FSK parameter settings?
4. Would oversampling approaches (receiving 250k signal with 1M FSK mode) be viable?

Any guidance on radio configuration flexibility or examples would be greatly appreciated.

[dp]

Any guidance on this is greatly appreciated