Missing Handshake Notifications in channel

[SX91]

Hello!
I've used the approach similar to the proposed one here, but sometimes the connected peer is not being registered.
Seems like it happens because the StateMachine.hsNotifyc is created as unbuffered channel, and writes to this channel are non-blocking (select + default), thus "skipping" some notifications if the receiver is "slow".

Any suggestions how to make notifications reliable?