If that works for you, then by all means continue inflating to 45psi. I'm surprised that over the years you have not worn out tires in the middle tread faster than on the side blocks as overinflation (which 45 is) rounds out your tires. While your specific tires can handle 45psi and even a max of 50, they are not designed to run at that pressure for maximum wear, comfort, fuel economy, and safety. Inflating them to 45 or 50 makes the center tread bulge thus making you run on less than an ideal tread patch. Traction diminishes, stopping distances increase. Honda recommends 33 psi for maximum patch contact, longest wear, and maximum comfort. I generally tend toward 33 knowing that the heat of the day AND rolling heat will increase that by a few pounds on its own. Like I said, your tire pressure is up to you, but beware of the pitfalls of going significantly above recommendations.FYI, I keep my 2018 Touring tires at 45 PSI. I'm one of those who ignore the recommendation and use the 90% rule of max PSI. My tire manufacturer max is 50 PSI, thus I inflate mine to 50x0.90=45.
This rule has worked well for me during the many years of car ownership. Your dealer may be applying the same rule for tire pressure. However, you might want to ask them their reasoning for using 45 PSI.
33 PSI for a 50 PSI max tire means your tires are only inflated to 66% capacity. Personally, this seems unusually low and more likely underinflated. But, then again, that's Honda's recommendation. So, choose what you're comfortable with.
As far as the TPMS goes, did you drive the required speed and cumulative time after selecting TPMS Calibration? Here's what the manual says (see the bold):
• TPMS cannot be calibrated if a compact spare tire is
• The calibration process requires approximately 30
minutes of cumulative driving at speeds between
30-60 mph (48-97 km/h).
• During this period, if the power mode is set to ON
and the vehicle is not moved within 45 seconds,
you may notice the low tire pressure/TPMS
indicator comes on briefly. This is normal and
indicates that the calibration process is not yet