Flippy openwrt and istoreos is safe?

I’m asking because I recently saw
https://www.youtube.com/watch?v=yHhdTRVvDFU
https://www.youtube.com/watch?v=Lc2hB2AwHso
And your network computer radxa com/products/#NetworkComputer
They run on some version of OpenWRT that I am not familiar with, namely Flippy OpenWRT and iStoreOS.
It has to be this version of Flippy OpenWRT, it can’t be OpenWRT?
Is iStoreOS a separate system or an overlay for OpenWRT?
Are both open source?

deepl translate