Questions about SE8R01 (NRF24L01)
The multi-slave (I don't congratulate them for the choice of wording) mode really is just a convenience function to give you "logical" channels at different adresses; it doesn't bring any new RF/network topology.

So, if you don't want 1:N communications, but M:N, just don't use it. Instead, address the packets like you want to, directly.

The device, reading from the state machines, doesn't have any arbitration – the Medium Access Control (MAC) strategy is a plain, unslotted Aloha – and I can't even seem to find an exponential backoff in there, so, errr – don't use this for anything where you get a substantial probability (say: 5% or higher) of two packets colliding in the air – you'll get colliding retransmits, new transmissions colliding with these retransmits, and even as the first transmitters reach their max number of retransmits and just give up, you'd then get ACKs colliding with retransmits of the second ones; a vicious cycle.

So, this is totally OK for e.g. a network of nodes that occasionally send a short packet; it's not OK once on average, more than ca 15% of time the air needs to be used by packets. (Eg. if the average packet + ACK is 1ms, you must not transmit more than 150 packets per second in the whole network; 150·1ms = 150ms = 15% of 1s).