A long time since I have flown out of CNS and, for other operators, done escape sums there, but I guess the hills haven't changed all that much.
Main problem with tiger country is tracking accuracy/reliability and the splays required by the rules .. which, of course, can vary somewhat. With that as the basis, one sets about designing a way for threading one's way through the hills.
A significant concern, of course, is that we need to keep it reasonably simple for other than FMS escapes so that the pilots, in a high workload situation, don't have to work wonders as this and that goes wrong along the way.
Standard departures without high accuracy GPS tracking need to be padded somewhat more for all the usual things which can go wrong .. hence the early turn .. which is a simple way of getting out of CNS15.
As a rule, I don't like going up a valley - unless there be no other option - as it limits all your options in the event of either FMS failure or other failures/problems. However, if the splay rules and tracking accuracies can be met, such an escape, philosophically and for risk considerations, is not much different to the risks associated with the usual V1 failure and similar low probability situations.
I recall with a bemused smile, years ago, Roger G - the then ops eng boss at AN, observing to some of the pilots who were being vocal about performance failure risks ... that, perhaps, they should also harass the structures guys in similar vein .. after all, it is not unheard of for wings to fail and fall off ...
I might add that AN had a very healthy tech services/flight ops culture and questioning was never (to my knowledge) suppressed (even if it might have been a PITA to tech service folks on occasion) .. If you are fortunate enough to work in such an environment, then do consider yourself particularly fortunate. Tales abound of less well-structured and healthy cultural flight organisations ...
As others have observed above ..
(a) AEO and OEI are quite different animals.
(b) SIDs may be less than useful for the OEI situation.
(c) AEO can become OEI at any point during the procedure .. which complicates matters to some extent. The operator whose ops eng support delves into this consideration routinely should produce more useful escape procedures than others .. I have heard that some organisations shrug their technical shoulders, do the regulated bits only, and leave it to the commander to sort out the non-prescribed out of left field situations. As we all should realise, that's somewhat easier said that done for the guy/gal in the LHS.
(d) TO and missed escapes are quite different animals due both to starting point and configuration/speeds. These differences may produce either similar or dissimilar escapes depending on the particular terrain/elevation/OAT/wind circumstances.