Probably the main participants in this thread have been doing so if only I could comprehend all of what they wrote.
If that is me, then in my exchange with Fafner, we were looking at analytic propositions that either seemed to say things about 'the real world' or might be linked to propositions about the real world.
Since our whole object in seeking such a 'synthetic a priori' proposition is that it would provide a sound basis on which to apply logic and thus discover other truths about the world, then they ought to be express-able as logical propositions.
I did not think this was possible. I thought that if you analysed them then they would always be found to contain some form of self-contradiction.
As things developed and we looked at examples, we found this disagreement was a reflection of different ideas about the nature of logic. Fafner saw it as a refinement of ordinary speech, but I saw it as more like maths.
I think this is how philosophy works generally, like the Socratic dialogue. Somebody says something; it is usually in the form of an 'a priori', but when we dispute it we find that actually our respective positions rest on pre-suppositions that perhaps we were not aware of. It doesn't follow we therefore 'agree', but I would say that it constitutes progress.
But to briefly take up Mlw's invitation, I don't see the problem with Kant's "transcendental ego". He uses the term to distinguish the fact we can be aware of ourselves as individuals through reflection, but we cannot experience ourselves in the same way as we experience objects. I do not see how you can interpret that as implying 'a kind of spirit enveloping existence'.