NemesisUK

If you go to the size suggested your speedo will under read massively, you would be doing nearly 77mph at an indicated 70mph. The difference in rolling circumference is 6.9%. The recommended max is 2.5% https://www.tyremen.co.uk/tyre-size-calculator

Sticking them on with tape designed for reg plates is the better way to go. They will be more secure, less likely to be stolen and won't promote delamination/discolouration.

Doesn't your insurance have glass replacement cover?

Doesn't appear to be the case in the RC. The handbook states operation condition is the Power switch is in the ON mode.

If the potential financial lose is great enough the insurers will send an expert to interrogate the ECU and any change in mapping will be discovered. Do not believe those claims from remap companies that their remaps are undetectable.

No offence meant but you haven't put the bulb in upside down? I know it's possible on some (MB) models, maybe also on the LS?

Must admit to thinking all hid lights were projector?

Check the condition of the engine and transmission mounts

All automotive leather is coated and sealed, so conditioner is a waste and possibly detrimental to the finish. Use any proprietary cleaner or simply use luke warm water with a little wool detergent. Don't soak the leather, dry naturally.

Dyno runs are great for before and after comparison figures demonstrating any increased output due to tuning work but as a stand alone measurement, one would need to show calibration certs for the dyno for the figures to carry any weight.

Not in my experience with Lexus Swindon, who have as Rayaan has said above do the check each service. I was speaking with their geometry tech only two weeks ago. All he does is geo checks/adjustments.. I just wasn't sure if the checks were done on the RX as on my RC.

I think the 'problem' is with the OP's dealership not Lexus per se. Structural Blue is clearly easily repaired as per the video (in fact it's an easier respray than the 4 layer Sonic red, Ultrasonic blue/ Naples yellow and Sonic titanium). Sourcing the paint shouldn't be an issue either. Obviously not common as so few cars out there with this colour but should be an issue IMHO. Try a different dealership, or as suggested above, contact Lexus UK directly

This might be of interest to you "Lexus Structural Blue, paint code 8Y0 is a standard basecoat/clearcoat system. This amazing color looks like it might be difficult to repair, but actually, it's very simple. Follow this recommended procedure from PPG to perform a small spot repair on this color. Structural Blue was developed by Lexus and VIAVI Solutions Inc. It’s based on the coloration of the vibrant morpho butterfly, a species found in Central and South America. The butterfly appears blue in color but does not actually have blue scales in its wing surfaces. The blue color — which varies depending on the ambient light — is achieved through light interference. PPG has introduced a training video to assist paint technicians with refinishing Lexus automobiles sporting the OEM’s Structural Blue finish. The video has been produced to dispel the notion that complex colors require a complex refinish process. In fact, it's not difficult at all." I was quoted £1100 to repair a simple stone chip on my Sonic Red painted bonnet..

Broken wire(s) in the loom going through the door hinge bellows?

I was surprised to find that a full 4 wheel alignment check as standard on full service on my RC (it's listed on the service check sheet, any required adjustments would be additional charge), on my 2016 RC final service it was noted that the inner edges of the rear tyres were showing wear. This was normal for my model, according to the service manager. Does the RX also benefit from a full 4 wheel alignment check at service time?