I have been using a cash account to day trade equities since 2016, before free commission. I'm not going to take this conversation personally because I know how complicated it is to get your head wrapped around GFVs.

Buying the security without having settled funds is a good faith violation.And per your own link - if you sell that position before you have deposited funds to cover that settlement, as in, if you attempt to simply sell the position and let that pay for the original purchase- you have a freeriding violation.

You cannot regularly commit GFVs in a cash account. You made it seem like you can but you can't, even if you hold it overnight - you have to deposit cash and let it settle to cover that initial purchase. These are not broker specific rules, these are banking regulations. It's basic accounting.

This might have a bit of leeway if you're trading cash-settled option. My experience is in equities.As you pointed out, 3 GFVs in a year and your account is restricted at a minimum. But many brokers will simply close your account - mostly because it shows you don't know what youre doing and youre making a mess of their books, making regulators look at them, etc.

Edit: TL;DR If you buy a position with unsettled funds, that is a good faith violation whether you hold it overnight or not. The purchase is a violation. Selling the position before you have added money to cover that settlement is another violation. You cannot do this regularly, as you implied.