Likely being the CR2032HR variant (=Heat Resistant, temperature-range from -40 degrees Celsius to +125 degrees Celsius)
The CR2032HR's thickness (height) is 3.2mm versus the CR2050HR 5.0mm
So a difference is 1.8mm, which is not that much difference, as there is in that respect "plenty room" within the BMW TPM Sensor to mount them.
The bigger difference is the mAh-values, meaning how much current it can maximum provide measured per hour, before it drops to 2.0 volts (the state at which it should be considered "empty")
The CR2032HR ia 200mAh, whilst the CR2050HR is 350mAh.
(but the CR2032HR has a higher acceleration Resistance of maximum 3300 G's versus 2000G's, which is, according to the manufacturers equivalent to acceleration when driving at 300km/h & using a 17-inch wheel)
Bottom-line: the CR2050HR should a fine replacement (too) for a dead battery and probably will last a bit longer versus the CR2032HR.
Getting a slight difference in reading the actual pressure often comes down to what tool you are using as a reference to compare the measurements with.
El cheapo tyre-pressure readers often give very slanted results.
Whilst investment in a good digital or analoge reader often give more accurate results.
TPM sensors, including BMW's, are so-called temperature-compensated.
Meaning, the pressure displayed on your dashboard is the pressure as if the tire is at 20 degrees Celsius.
Which a tire seldom is, hence also the reason the pressure does increase when the tyre does get warm.
Therefore you should always measure the pressure before riding and preferably pressurise your tyres a wee bit above but never below the desired pressure.
Where it really comes down to your personal preferences, and your brand of current tyres, but not excluding what the motorcycle manufacturer states in the user manual about tyre-pressures.
I like harder tyres as the bikes rolls & corners better for me, compared to what BMW dictates in my user manual.
