I quite often use an external monitor when making videos with Olympus OM-D E-M1X. I either have an Atomos Ninja Inferno recorder or a Feelworld FW568 field monitor. The recorder or monitor gets the info via an HDMI cable.
The problem with this method is that most cameras have a micro HDMI port. It is ok to get the signal from the camera to the monitor or the recorder, but the micro HDMI port is not usually very durable.
I had a video gig this week and I used my Manfrotto 561B HDV monopod. I rested the camera against my body. When started to shoot video again the monitor was black. Then I realized that the HDMI cable was bent and was still attached to the camera. This usually means that HDMI port in camera is broken.
But luckily it was the HDMI cable that was bend. The port on the camera is ok! So it looks like the E-M1X can not only be washed under running water, but the HDMI port is more durable than the HDMI cable!
disclaimer: I am an Olympus Visionary. Some of the links in this post are Amazon Affiliate links. If you buy something from Amazon after clicking the link in this post, I will get a small commission, but you do not pay any extra. It is a nice way of supporting my YouTube-channel and this blog.