Blue Iris

I want to have multiple monitors (5 or so) around the property with 4 mainstream camera views on them. Probably different monitors with different camera views.
I was thinking raspberry pis running Ui3 to feed the monitors. Is this concept realistic? Thanks.

Not 100% sure but as you can control access viewing of the cams using groups you’d need at worst 5 diff logins so that the groupings access and layout can be set up as you want.

There's no reason why this shouldn't work. Just make sure the computer running BI can encode 5 streams and make sure whatever Pi version you use can decode whatever codec you pick for the streams.

You can verify that the BI computer is capable of doing it by opening 5 browser windows and logging into all the different streams. Don't minimize the windows though or the streams will probably pause. If it has trouble, you might need to add a GPU or two.