HDMI output HMI recommendation

S7-300/1200/1500 CPU webserver:
Advantages: "free", no extra hardware, does not add non-industrial equipment into the application.
Disadvantages: Programming is not as easy as a dedicated HMI solution. Any change to the webserver requires a hw download and stop of the CPU.

edit:

There is no fancy graphics or animation. A few multi-color lights and some timer data.

Click to expand...

I think this is the kind of application that would be fine to do with the CPU webserver.

https://www.automationdirect.com/c-more/headless-hmi

C-More Headless EA9-RHMI. HDMI port to your large screen TV.
Here is a series on the programming of the series. The headless cmore is listed near the end of the list.

I hope this helps you out.
Regards,