Subframe connectors for a driver/cruiser, necessary to weld to floor?

If you set the car up with bigger sway bars, wider stickier rubber, and poly bushings, it will most certainly benefit from subframe connectors keeping the body stiff and forcing that upgraded suspension to do its job. Not everything about these cars involves just a straight line.
It all doesn't matter unless you have traction.
If you read his original post he's only doing smokey burnouts no racing.