Welcome @codrin44
Sounds like you have it all planned out!
Like Rich I am wondering what Philips LEDS you are using?
Reason I ask is I replaced some of mine with Philips Ultinon Pro6000 where I could;
W5W Sidelights
P21W Rear Indicators
These didn't show any LAMPF/LAMPR CANBus errors either.
I also replaced the twin H7 Halogens with Philips GT200 which are halogen not LED leaving the factory Xenon intact as I was concerned about beam patterns of Xenon & Halogen vs LED with the original headlight reflector optimised for the original bulbs.
I did try a pair of P21W as rear stop/taillights but they didn't work at all due to the K1300 using modulation to switch between stop/tail rather than two separate filaments I suspect.
Front indicators are still using standard H21W as I didn't see a suitable replacement in the Pro6000 range although I would need orange/amber because I have clear indicator lenses which really clean up the look of the front end and make it look much more modern IMHO.
Interestingly all the bulbs I looked at were the original Osram bulbs looking at the dates on them the only failure being the right hand sidelight which was blown when I bought it only 2 weeks after a full BMW service.
While on the point of service I would definitely take a look at the air filter(s) as the one on my GT was original and was filthy.
I fitted the Schroeder BMW emblem LEDS which act as DRL & turn indicators and also have a SoundBomb both driven by the Hex ezCAN which allows a few tricks such as the ability to strobe and also dim the emblem DRL automatically at night and program in a variable delay when the horn button is pressed so a brief press sounds the factory horn while anything longer than 0.25 seconds in my case also brings in the Soundbomb as well.
It's always fun watching the MOT tester jump when he tests the operation of the horn...

I would be very interested to know how you get on with both fitting and riding with the Lust lowering plates as I am considering fitting these to my GT. Most people who fit plates seem to fit risers but I can barely get both feet down on the standard bike with the lowest ESA settings!
When I calibrated the ESA with the GS911 it did lower the bike just a little to a position I was much happier with but that lifted back to the normal ride height shortly after so only a temporary solution in my case.
Looking forward to you posting the photos...
Thanks & kind regards,
-=Glyn=-