I would always use a tax professional, not a lawyer, from a personal perspective, or I would use the two combined.

For example, a UK lawyer (and a HK lawyer too!) are not on the hook if they write your will and it ends up a mess tax wise. Their job is to write a will- irrespective of whether it works in all the tax jurisdictions concerned. I would always seek joint advice in that area from specialists.

Additionally most UK tax lawyers I know are good at the theoretical side of tax and talking about tax cases- but calculations and actually applying it? Dreadful. They bring down the pass rate of the UK tax exams substantially (yes, there are some who take it).

On top of that, I would only ever seek someone who specialised in the area I was looking at. There are too many people who try to be broad or think they know what they are doing when they don't as certain areas are complex and require on the job extensive experience- you've probably had a bad experience with a bad CPA.

Simple as that.