I've heard multiple people say this as the reason for not using Firefox, but I can't remember if I ever had sites not working on FF. Does it happen often for you?
I don't know what the extended warranty price is in your region but for me with my XPS 15 9500 I would recommend it. The repair guy has been at my home like 5-6x. Stuck pixel screen replacement, factory trackpad defect > replaced > which caused the fingerprint reader to stop working> in the end it magically fixed itself. Use the phone line with your "premium" support the whatsapp helpline fucking sucks.
I hope they don't screw the auto OC. I have never OCed but my motherboard did decide once that my normal default core frequency of 3.2GHz was too low, and did an automatic unstable OC which resulted in a nice and high 1,2 GHz -__-. I had to switch it to a manual OC, and then back to automatic and it was fixed.
The simplest thing I printed is the one I'm most happy about, I had a power bar dangling beside my bed for all my chargers and I printed 2 small clips and it holds it great.
I printed bookcase supports, an air filter and tons of custom boxes for electronics. I learned the basics of SolidWorks so I could design stuff for my printer (ender 3 S1)
I know it has been fixed in a kernel patch for the other 95x0 models and should be ready in some 6+ kernels but I'm not sure for the 9500