Not all that small, but there's a lot of overrides! Uncommenting the commented-out line moves the text back, so the Largo is correct but the Presto is wrong.
-------------------------
Wednesday, February 14, 2018, 3:25:17 PM, you wrote:
> On 14.02.2018 13:34, ptoye wrote:
>> the Largo metronome mark is too
>> far to the right as it seems to be aligned to the first silent note rather
>> than the clef or time signature.
> That seems like a bug to me – I think the MetronomeMark should be
> aligned the same no matter whether it’s in a context of its own or not.
> I suspect it’s also possible to override to which grob it is aligned,
> but those overrides are complicated… can’t look it up right now.
> Can you give a minimal example?