[perl4ever]

"(2) if you are able, express to your current manager that you'd be interested in learning additional skills and possibly making a - deliberate, smooth - career transition."

Based on my experience, that is unlikely to work. If you are not in an entry-level job, then your employer/supervisor, if reasonably intelligent and competent, will recognize that you're far more valuable doing what you've always done. So they may be nice to you, but they will resist. It's the flip side of the Peter Principle.

I think it's a better approach to get an entry-level job in the field/organization you want to transition to and then expand your job with the stuff you want to be doing.

[foobarchu]

Not necessarily. I would argue that any reasonable intelligent and competent employer/supervisor would recognize that an unhappy employee is going to provide diminishing returns over time, and the employer would be better served helping them explore related opportunities in the company. I've seen programs to help employees do exactly this at every place I've worked.

The only cases where I think it would usually be a problem are if your end goal is not with the company, or if the end result is seen as a going down the ladder (example: QA personnel moving into development is a positive move, but developers becoming a tester is often seen as a negative move)