If you have devices with single pole switches you could end up switching the neutral.
Which for most small appliances really is of no consequence. Far too much is made of this supposedly "dangerous" situation in the U.K., but the fact is that in most cases it really doesn't matter which side of the circuit a single-pole switch on the appliance opens.
The argument for, let's say, a kitchen blender, is generally along the lines of "But the motor will remain live even when the switch is off." Yes it will, but so what? The motor is still safely contained within the appliance, insulated from anyone touching it, just as when it is running.
If the appliance is double-insulated with a two-pin plug of the type used across most of Europe, then there is
never any way to guarantee which side of the circuit a single-pole switch will end up in, because the plug is reversible in all the types of outlets it will fit. The same was true of the old 2-pin British plugs & sockets.
There are some cases where polarity and switching may be considered important, but for by far the majority of portable appliances, it doesn't really matter.
Personally I would go round rewiring all the sockets so that the live is on the right pin.
If you want consistency throughout the building that's fair enough, but for the practical purpose of trying to guarantee specific polarity of connections to devices it won't do any good, as the European cordsets can be found with brown & blue connected either way around (as well as the 2-pin plugs being reversible anyway, as mentioned already).
