Unchanged, ie not increased it!
I found, probably the same as you Ashley, that with the SSL supplied 20mm spacer fitted below the stub axle, ride height remained roughly the same on my Roadster.
No grounding issues either excepting the odd rogue speed bump which happened before I fitted the SSL kit as well. As it's the gearbox cross member that makes contact on these rare occasions, there is virtually no way the sump could be vulnerable.
