It looks like the meter is installed in position ‘D’ which is acceptable.
The guidance suggests avoid install the meter after a double bend in two planes. Your meter is installed before the double bend. So this should be fine.
Here’s the emonHP install guide:
Here’s the Axioma manufactures manual, they don’t specify any straight section of pipe requirement:
The installation position of heat meters is quite forgiving, the main issue we’ve seen is errors due to air in the system: