Lamp warning can be fixed, the cheap way is to buy canbus ready parts or mount a resistor , both canbus ready and the resistor route works the same way. Tricking the canbus by drawing a big current and burning of as heat in a resistor. No plus with this route.
A bit more expensive is to take the bike to a dealer and have them reprogram the canbus to accept the lower current draw, it cost more than resistors but there is also a plus, doing it saves on the amps the bikes draws just by being up and running.
So the lamp warning is an easy fix either way, harder is to find descent LED turn signal indicators when it comes to their light output and looks. The BMW originals are way too expensive when also weighing in the cost to have the bike reprogrammed.
All in all i got a quota of 750USD if i buy BMW parts and reprogram. For indicators thats is just pricey. Then i found the chinese replicas of bmw but i can not find any good video or review on them.