Sadly this wasn’t easy.
In the Quotes / Line items module, when you are entering the type of discount there are two types by default: Amount (Amt) and Percent (Pct). Someone asked me to change the default from Pct to Amt. I logged in as admin, went into Studio, went to the Line Items module, went to ‘Fields’ and, like always, changed the default value from Pct to Amt and saved.
Then I went to a test quote and… it didn’t work.
Then I went to Studio ran a Repair / Quick Repair and Rebuild and I could see the mismatched database warning stuff and then I executed the repair. Everything said it was synched up. This must have worked, right?
So finally, I edited the actual dropdown for that field (called “dropdown_list” if you are looking) and moved the Amt to the top of the list above ‘Pct’ and.. now it’s default..
So I guess you can’t set a default here for some reason not sure why, but this workaround might help you.