Thank you. And, uh, sorry I know I'm a year late on the mark here.

There's definitely some considerations to be made here, but it needs some more thought about the precision of these values.

float could probably be dropped in most cases, since these values will already be implicitly float (eg: data.oxidising / 1000), or implicitly int where float will add no extra granularity anyway.

round(float(bme280.get_pressure() * 100), -1 ) is also self defeating, since round(N, -1) will round that float down to the nearest ten anyway, eg:

>>> round(24.5, -1)
20.0

I didn't know about mqtt's retain feature. TIL!