How to get rid of lines surrounding assets?
Looks like you are referring to the selection brackets for an object(s) that you have selected. To remove them, right click on the [Standard] viewport label >Active Viewport settings>Preferences, and uncheck Selection Brackets.
I am using Max 2022, but I think the exact name of the submenu and per view preferences may vary in other versions of Max. In Max 2022, this setting is a per viewport setting. In Max 2020, there was a checkbox in the panel to apply the settings to all views.
