Yeah we do something like this in frostsnap, it used to explicitly be called aux_rand. We're just seeding ChaCha20Rng with our secret share, and using the nonce counter to increment 
Would keeping aux_Rand a counter be used in something like FROST?
nostr:nprofile1qqswrlemlh2wgqc4jkds3d8ueqj9a2j3gcm7r48v9tskdd6rxsd7rtcpzfmhxue69uhhqatjwpkx2urpvuhx2ucpz3mhxue69uhhyetvv9ujuerpd46hxtnfduqjxamnwvaz7tmwdaehgu3wwfhh2mnywfhkx6mzd96xxmmfdejhyuewvdhk6jg4k33 nostr:nprofile1qqsdnpcgf3yrjz3fpawj5drq8tny74gn0kd54l7wmrqw4cpsav3z5fgpz4mhxue69uhk2er9dchxummnw3ezumrpdejqz9rhwden5te0wfjkccte9ejxzmt4wvhxjmcprpmhxue69uhhyetvv9ujuumwdae8gtnnda3kjctvl3x2lg
Discussion
Nice. Thanks to nostr:nprofile1qqs0h0rh0ju253j0k6njmkwfuat5ztrz4wlkfepppkkntzvrtdvh2fgpr4mhxue69uhkummnw3ezucnfw33k76twv4ezuum0vd5kzmp0qyfhwumn8ghj7mmxve3ksctfdch8qatz9uq3xamnwvaz7tmsw4e8qmr9wpskwtn9wvhsefcut2 I know what that 'tag' thing is.