Hi D,
This is new territory to me so please excuse the questions if they are not very clear.
I've heard (mainly a few BATGAP interviews) a notion of living purely in the present. I assume that means being unable to imagine consequences of potential actions. It seems the creative process is often not about running with the first idea but playing out the ideas and throwing most of them away. Not being able to perform that type of activity seems more handicap than advantage.
I've also heard reports of sensations getting the same priority, so for example loosing the ability to concentrate (obviously not everyone on BATGAP reports that). Again it is hard to see the advantage of that - I mean sensations are not equivalent in the real world - admire the big wall painting or notice the small flicker which is the shadow of a saber tooth tiger

Another example, I like being able to reach a state of flow in an activity to the point of not hearing/seeing things around me, I suspect it is more effective for the particular activity.
When Shinzen states "sane grandiosity" that seems to suggest a real ego at work - but maybe not an ego functioning on fear ?
I should have framed the subject better. I don't think suppressing the sense of self is a good thing. The way Shinzen explains how the self is experienced is like a wave function. This seems very different from the way it is typically described on this forum (your description aligns with what I woulds have expected). Have you watched the video?