Perfect Participial Construction

I was wondering how to interpret the perfect participial construction of the subordinate clause as follows:

'Having worked with many clients over the years', I have been occasionally surprised to watch as one of them experienced an amazing “aha!” of recognition and had an internal shift after watching a movie. These clients were able to identify with characters who had struggles similar to their own. But while they identified with the characters, it was also somehow easier to maintain their distance “outside” the experience.

Q. We learned that the tense of 'Having p.p. (participial construction) ~' precedes the tense of the main clause in terms of tense. Is that absolutely correct?
Q. Which paraphrasing is correct in interpreting the meaning of the perfect participial construction, i.e. 'Having worked with many clients over the years'?
1. As [Because] I worked with many clients over the years, I have been occasionally surprised (present participle) to watch as one of them experienced [past tense' ~

2. While I worked with ~

3. While I have worked with ~

Thanks for your help.