When importing a custom BOM you may decide to change the BOM type (i.e. from Top Level to Indented). More often than not your columns will then shift which can cause issues with word wrapping and row height which can take some to manually readjust.
To avoid this, right click on the top of each of the column headers in the BOM and select Formatting>Lock Column Width.
Each column will now display a lock icon and the columns will not change when switching BOM Types or when attempting to manually edit.
To unlock the column width, follow the same steps as before and unselect "Lock Column Width" once again.
The "Lock Column Width" can be saved in the BOM Template so that this edit does not need to be performed each time. To do so, ensure the BOM is selected and select File > Save As, change the "Save as type" to "Template (*.sldbomtbt)" and save the template file to your desired location.