You can only add 10 resources to a single item buildup however you can activate the Composite Item function. The Composite Item feature allows you to create up to 20 single buildups against 1 item. This means up to 200 resources could be added to a single item.
To turn on and create a composite follow the following steps:
From Estimating/Valuations, click Layouts and ensure the Composite Item feature is turned on.
In the Composite Item window, click Add
Enter a Description, Qty, and click OK
Select the new entry in the Composite Item window the Single Buildup window will show a blank buildup of 10 resource rows.
Note: There are some limitations with the composite item function running alongside comparisons. You cannot have the same resource for Comparisons in multiple single buildups within 1 item as the comparisons will only ever update 1 instance of the resource.