...no contingency procedure due to obstacles...
I take that to mean that there is no ET or non-standard AA published in your Company performance data?
I would caution that just because there is no contingency procedure, it doesn't mean that there aren't any obstacles - just that following your SOPs will give you the required terrain clearance. It is
not a licence to invent a novel OEI procedure and see if it works! (Or not...
)
As far as the effects go, an early clean up might compromise the second and third segment obstacle clearance (compared with normal). A later clean up will probably give better clearance initially but there's the possibility of going below the net flight path later on if it's tight.
If you're taking off over the sea, then I suppose it doesn't matter (tall ships excepted!) but I'd be very wary of doing anything non-standard under
limiting conditions as it's sometimes not obvious where the critical performance limitation is: could be just off the end of the runway, could be 10 miles away round a corner...
We use 1,000'AAL unless otherwise specified.