This must be well known to many; it's all over the internet and the context is e.g. here

The Nokia workaround
is a poor solution because, in the UK at least, 3G is around 300kbits/sec whereas HSPA is 5x to 10x faster.

According to an official Nokia post in that thread (around Nov 2012) Nokia service centres have been issued with instructions on how to modify the PCB.

It's fairly obvious to me (electronics hardware/software developer) that the problem is the much higher power consumption when running HSPA, which collapses the power supply and crashes the phone.

The specific issue is that Nokia UK's website, "Buy" link, points to Amazon UK and all sellers there are grey imports, which Nokia service centres won't touch.

What can one do?