Hi Michael,

Don't think you will find a convention, out of the 5 modeling apps I have only MoI and modo have the same layout by default.

You can change each viewport to any other view in every one of these apps except MoI. Modo is currently the most flexible allowing any number of viewports to be added to the screen as well as defining what each one is. With all that flexibility it doesn't really matter what the default is as you can customize the layout to suit yourself.

Default 4 port layouts: