TooHotToFly - No! The SEP Revalidation Proficiency Check and PPL Skill Test are entirely different. Although JARs require a SEP Class Rating 'Renewal Skill Test' if a pilot doesn't meet revalidation rerquirements, in the UK this may be done by the same SEP Revalidation Proficiency Check (so long as you're not more than 5 years lapsed)! The only real difference is that if you manage to do your Revalidation Proficiency Check in the last 3 months before the date in your FCL150CJAR, your SEP Class Rating will be remain valid for a further 2 years from that date, NOT the date of the Proficiency Check. However, if you don't manage to do your check in time, then you may not exercise the privileges of your rating until you have satisfactorily completed your check - and your FCL150CJAR will show the next revalidation date as being 2 years from the date of the check. In either case the same Form LPC SPA will be used.
For SEP Class Rating revalidations or (<5 year) renewals, there are NO navigation requirements; neither are there any Skill Test navigation requirements for someone wishing, for example, to add a SEP Class Rating to an existing JAR-FCL licence which has some other Rating.
The SEP Revalidation Proficiency Check is very straightforward: Steep turns, a couple of stalls, an off-aerodrome PFL, a couple of circuits including a go-around and an EFATO. Best of luck!!