verbs - How to understand the contractionしていて、/-てて

I am trying to better understand this sentence:

金さんは、微妙なニュアンスまで気にされてて、すごいですね。

It's amazing how interested you are in these subtle nuances.

Is the following an accurate understanding of this contraction? Written in what I perceive as basic, plain Japanese (without honorifics), perhaps the sentence would read as thus:

金さんは、微妙なニュアンスまで気にしている。それは、すごいことだ。

Then the " いる。それは、" can be contracted to

金さんは、微妙なニュアンスまで気にしていて、すごい。

Then the する is put into 敬語 and further contracted.

金さんは、微妙なニュアンスまで気にされてて、すごいですね。

I know the order of this process is arbitrary, but is my understanding correct? If anyone could explain what the していて、/-てて is doing specifically, I would appreciate that as well.