I think you should get lightweight wheels instead. Get some Enkei RPF1 wheels.

 

in the 4th gen GS forum, there are problems with the two piece factory rotors (which prompted lexus to issue a TSB).
the vendor that handled the aftermarket solution is R1concepts (CL vendor).

https://www.clublexus.com/forums/cl-...rake-pads.html

you may be able to work with them on a solution for the LS.
though keep in mind the demand for a two piece solution is much less for the LS than others, so they may be less inclined to help.
they may charge a ton for the R&D for a one-off product for you!

 

Posted earlier on two-piece rotors as a way to reduce unsprung weight by up to 8 pounds.

Visited with Mathew Roskey, USA Sales Manager at DBA regarding continuing availability of front two-piece rotors for our LS400.

DBA will produce two-piece LS400 front rotors in 50 piece production runs.

https://www.dba.com.au/products/prod...ors/hd-5000xs/

Matt advises actual weight savings approximately 3 - 5 pounds over stock rotors

DBA offers single piece rotors with various options

https://www.dba.com.au/products/prod...tors/hd4000xs/

One and two piece rotors incorporate the same metallurgy:

https://www.dba.com.au/tech-zone/pro...nology/xg-150/

and heat-treating:

https://www.dba.com.au/tech-zone/pro...hnology/tsp-4/

They claim a more efficient "Kangaroo Paw" cooling vane ventiation configuration.

https://www.dba.com.au/tech-zone/pro...w-ventilation/

Anyone interested in measuring peak rotor temperatures, DBA uses thermographic paints to allow user to determine peak temperature thresholds:

https://www.dba.com.au/tech-zone/pro...aint-markings/

If questions, feel free to contact Matt.