Kakute F7 and FrSky Telemetry Passthrough (new SERIAL?_OPTIONS parameter)

Hi, everyone.
I’m trying to get telemetry from Kakute F7 in my Taranis using Yaapu script and FrSky Telemetry Passthrough using FrSky R9 Slim receiver. It works okay on my Pixracer R14, using the FrSky SPort output. In Kakute F7, my S.Port receiver wire is connected to SERIAL4 Tx and SBUS out is on SERIAL6 Rx. I’ve setted SERIAL4_OPTIONS to 1 to invert Tx, but telemetry still does not work. Does anyone figured out how can we make it work? I’m using Arducopter 3.7 dev (latest). Thanks in advance.
Regards.