The way that I address the problem,
BOAC, is to design ALL OEI procedures, without exception, to terminate in a Holding pattern where continued climb to the MSA may take place. Sometimes (conveniently) the holding pattern used is a published one, but more often than not, one of my own design.
The intent is to provide full FAR25 (and other equivalents) obstacle clearance guarantees all of the way until the MSA is reached, whereafter the pilot may transition from the 'tighter' FAR25 requirements to normal PANS-OPS terrain separation. All of the procedures are notated "Obstacle clearance
BEYOND the MSA is the Pilot's responsibility. The WAT limit for the associated RTOWs considers the FAR25 en-route climb requirements at the MSA.
It may sound snobbish, but I think that any OEI procedure designer who fails to give guarantees all of the way to MSA is falling down on the job. A performance snob I may be, but I sure sleep much better knowing that 'my' crews are protected all the way.
I've mentioned before that I don't do the P/E for the aircraft that I actually fly, and there's some horrendous CFIT possibilities built into the procedures employed (which stop short of MSA).
Over to you
Mutt.
Regards,
Old Smokey