I thought I would test the turn signals today with Amber PY21W LEDs.
I tested with both 30W and 50W CanBus compatible LEDs and they worked fine as hazard flashers but unfortunately they suffered hyper-flashing when used as a turn signal.
This can be rectified with extra load resistors but I do not like using them.
They are easy enough to fit but need a good air space as they can get very hot and must not be mounted on any plastic part. They also need to be the correct size rating for the circuit they are for. There is also a danger that they may overheat and ignite (that's very rare).
Instead I have fitted these Osram Diadem PY21W bulbs I had spare in my collection.
They are practically invisible as compared to the standard amber 'egg yolk' appearance.
I found some in Amazon:
They come in either Chrome or the Diadem (which is the style I fitted).
Very easy to swap the fronts; the rears are a little more fiddly and not really worth changing.