220VAC or 110VAC

I live in this country to enjoy retirement, not to plan, design or implement any electrical equipment, so there is a very slight chance that the following assessment has flaws:

This country probably has no standards or regulations for electrical engineering, if they exist they are hopelessly outdated, not properly distributed or ignored.
At best, professionals more or less rely on standards issued by the European Union.

The smartest way to market anything with a cord and a plug in the EU is to liberally use the EC logo in all documentation and add an EC compliance certificate, listing a random number of EN-xxxx-yyy standards. Because all European countries have their own (historical) standards and cannot agree on anything, most EN standards are translations of local ones that may be several decades old.
The xxxx is the year of issue, followed by the document number. For something as simple as a mains cord there are dozens of contradicting standards and new releases.

Now back to your question.
For an EC standard to be issued that recommends a switching charger over a transformer, the authorities must be made aware of its existence and the concept understood. I think that until today, such is not the case.

A switch mode charger provides better isolation and offers more versatility regarding input frequency and voltage than any transformer can.

 

This is a very worthwhile discussion for the evolving Marine technology.

Yes, the switcher is more flexible per its input.

However, a Marine isolation transformer has the advantage of known aging characteristics, known failure modes, and well understood in using a Megger to test and track insulation characteristics. When used with an ELCI (RCD) on-board, transformer leakage is continually monitored.

Also, you can have virtually any power and taps, and you are not mixing AC and DC buses in the same device used for isolation.

As far as frequency, I deal with two input frequencies UK 50 Hz and US 60 Hz. No need for wide range.

I can configure the front end taps, to accommodate either 230VAC UK, or 240VAC US. The input windings can be set up to boost from 120VAC US.

Mark Cat