Abelcine are running F3 courses at the end of May, which includes S-Log. I asked, they will have the F3 S-Log firmware installed, so that hopefully means it won’t be long before general availability.
The product code is CBK-RGB01, and will include S-Log, 4:4:4 and RGB. S-Log will also increase the already impressive dynamic range to near Alexa levels apparently. Interestingly also, it will also enable a WIFI mode using an adapter, product code CBK-WA01. The F3 seems to have many as yet untapped talents.