We work in environmental consulting, basically in contaminated land - he consults for our mutual client, i am the client's in-house technical strategist for the more... sensitive sites. Anyway, stuff he appreciates - strategic big picture, reframing, use of original analogy. Yes, I have no trouble backing up for when I'm suggesting stuff like that. It's great to have someone who actually realises and appreciates what I provide as a consciously produced thing - most people take it for granted like this stuff just magically seeps out of me or something.
Although sometimes he asks general topic questions but I feel I misread the purpose of the question. For a logical type, he can be rather indirect. What should I do if he follows through with playing down some ability of his - for example, not being able to pick up faster a language that we need for the work and that he is surrounded by, but that I'm mostly-fluent in? With my dual (and as between female friends), usually I would offer perspective and assurances. I have a latent feeling that this is not satisfactory. Is he looking for solutions? Should I actually ask him questions back i.e. invitation to expand on it? It sure sounded like a direct question, typically; it's just that afterwards I get the feeling that it wasn't. If that makes sense.
For work, though, I actually appreciate his dominant Te. Coz I can't be bothered to keep in working memory, what size piping we have connected to which treatment system, and whether we should just change the compressor. On the other hand I do have to pry him off of work when there's not nearly the time available for what he would consider to be 'worthy' work, and that less but delivered would be better than perfect but too late. So many many things go on at the same time for a project like this, each paced differently; it isn't kind on his weak Ni. He seems to be the most late, when he's personally producing work for me to look at, rather than just reviewing/fixing work from his team, for me to look at. Fortunately, I would usually have a plan B if not C, and would, er, usually have designed in means to compensate for this trait of his for when it would really matter.
Also, I envy his "unconfrontationalness" - he just seems unfazed. It's like a kind of inexplicably non-boring dullness, unremarkable until you think about it and realise how remarkable it is at coping with pressures without getting people all tense, or getting oneself worked up. It just calms me right down, which is great, because in this work you regularly have to deal with people trying to pass off things that don't make sense, as making sense, and that typically lights me up like tinder. It's perplexing how one can be 'dull' such that the dullness isn't dull, but rather intensely fascinating. You can imagine this conundrum can easily occupy me for hours.

On the other hand, when he
is late, getting upset accomplishes nothing. He does not get defensive or belligerent. And since there's no point in it, and he never disputes the facts nor the logic of why it shouldn't have happened, I can't get mad at him. And that's kind of annoying, if there were a point to feeling annoyed.
BTW, in what way would creative Si manifest outside of a personal life context? What are examples of creative Si, in a work context? I don't think I ever really think about it that way. I mean, I know in what form I appreciate it from my dual but we have a best-friendship - a different context and where I would actually be able to see and benefit from her Si.