LTC through ATEM TVS HD into HyperDeck Studio mini

I have 3 Pocket Cinema Camera 4Ks, each getting LTC in the Microphone jack from an external source. The external TC shows up fine. Each of these cameras is running into a dedicated Utlimatte 12 Mini HD via HDMI, and the Program Out is each connected to a dedicated HyperDeck Studio Mini via SDI; the TC carries over fine, and all 3 recorders are running the exact same TC. The output of the HyperDecks run into an ATEM TVS HD, and the Program Out is connected to a 4th HyperDeck Studio Mini. However, the ATEM seems to strip the timecode and I can’t think of a way to get the 4th recorder with the same timecode. Frustrating to say the least.
What I’m doing, is I am recording all 3 cameras plus a live switch. Usually the live switch is good enough, but sometimes I need to take the camera footage and re-cut some scenes, hence the time code is very useful. FWIW, audio is fed into the ATEM (Channel 1 and 2), and on occasion through an Audio to SDI Converter (Channel 5-8) plugged in between the ATEM and final HyperDeck, so embedding the LTC audio into one of the SDI audio channels is possible.
Any ideas, or am I stuck to aligning a hand clap in post?
I’m in no way a professional in this field, so please have some mercy on me if I’m missing the obvious, or if this topic has already been covered and I failed to find it in search.
What I’m doing, is I am recording all 3 cameras plus a live switch. Usually the live switch is good enough, but sometimes I need to take the camera footage and re-cut some scenes, hence the time code is very useful. FWIW, audio is fed into the ATEM (Channel 1 and 2), and on occasion through an Audio to SDI Converter (Channel 5-8) plugged in between the ATEM and final HyperDeck, so embedding the LTC audio into one of the SDI audio channels is possible.
Any ideas, or am I stuck to aligning a hand clap in post?
I’m in no way a professional in this field, so please have some mercy on me if I’m missing the obvious, or if this topic has already been covered and I failed to find it in search.