I've forgotten almost everything I knew about oboe playing, so forgive me if I'm talking out of my hat here. The series of notes you describe is part of a chromatic scale and I don't remember learning it, either
. *is not good at scales*
However, what occurs to me is that it is just that, a series of notes in a scale. With most practising conundrums (conundra? who knows?) I try to break things down into manageable chunkettes, and in this case would focus on the framework. I'm presuming, since it is chromatic, that you're doing said trills from the lower note first? I'd want to anchor that in my head first, Db D Eb E and however far it goes up. Next I'd work on making sure I knew how each individual trill went, but I think in this case might try first the Db-Eb, til I was sure of the transitions, then the D-Eb one til sure of those transitions, then tack the two together. Unless of course the whole series brings with it a sense of panic, in which case I'd start at the tail end of the whole thing
If any of the trills themselves is 'orrible to finger (that's the bit I can't now remember) - doing those with the dotted rhythms in each direction, dotted quaver semiquaver dotted quaver semiquaver and then reversing that, helps to make the finger transitions smooth. And I'd agree with your overarching approach of starting slowly and building up tempo.
After pairing two neighbouring ones, I'd add the next again to the sequence, depending on whether you're doing this forwards or backwards, and again, if there are beastly fingerings in the mix, I'd do them all with dotted as well as straight rhythms. My thinking in this is to get the trills to be automatic, and to focus instead just on that chromatic scale: the nearest parallel idea I can think of is when playing a piece where there is melody and accompaniment all in the one line, and you're trying to bring out the melody - you want to get to the stage where you can think melody and the rest slots in round it.
Is that a load of garble, is it something you've tried already, or do you think it might actually help?