There's plenty of room mmaaxx, it does restrict the flow.
I normally fit a hose about 150mm long straight into an old oil drum and do something else while it drains.
If your in a hurry it would be a PITA.
I would imagine the local workshop's mechanic's would hate them.
I do my own changes so doesn't worry me.
I also put a cable tie around it for my piece of mind even thought it is out of the way above the bash plate.
They are a great idea, no mess. I used to allways get oil all over the driveway and me
Macca