Hi,
It seems not easy to split at exact 5 minutes in gstreamer command. If you use jetson_mutlimedia_api, you can count frame number = 9000 to know it is exact 5 minutes(frate is 30fps). Can get IDR frames with this patch:
Xavier AGX : Video encoding crash - #15 by DaneLLL
However, in using jetson_multimemdia_api, you cannot utilize existing matroskamux, tcpclientsink plugins.
It is not possible to set max-size-time to 305 second in your usecase? Maybe for a try?