I would have mounted the boiler on the adjacent wall - just so you would have some safety when servicing.
It would have moved the flue further away from the windows also.
A little more pipework, but add it to the cost of the job!
The terminal then could have been fitted directly to the elbow, with no need for a clip.
Taking a second look at the pic, the boiler is slightly more protected in its current location by the eaves above.
May have been the decider as to why it was installed where it was.
Thoughts??????
Honestly - I would have put some clips on the pipes coming down the wall.
Some installers take no pride in their work.