Hello and thanks for the feedback
It looks like you need the Flight Directors set to on in order to set the FLX temp. The checklist has you set the FD's on before setting the EPR rating, but we'll check the logic.
The purple colour of the gear handle is intentional. While the manuals describe the colour as blue, we found that on real aircraft, its anything from a warm white to a very light pink. The purple colour seemed to be the most prevalent so we went with it. Check out a video here: https://youtu.be/MUiNikgXSWA?si=LbxXWlnA5WzosC7p&t=115
You'll see the CRZ alt invalid message anytime the FMC calculates that you'll not reach top of climb before top of descent. We'll have a look if anything is happening to the OPT altitude reading.
I'll add that to our bug reporting.
Thanks.
JF - John.