It's not likely to be the aluminium cabling itself causing the high number of dropouts. I too had a long run of aluminium cabling which did have an impact on my line performance but it should be a constant.
Your fault conditions are indicative of another fault although, it could still be related to the aluminium itself. For example, when copper meets aluminum or when the aluminium cabling meets any other metal in a connector, those joints may suffer with corrosion due to dissimilar metals which would be impacted further if moisture is present.
My point being, rather than using the fact that aluminium is present in your line, it's poor performing, please change it approach, try the "my line keeps disconnecting, a particular junction box/underground duct has suffered with bad connections in the past and is likely to be the fault - by the way, the fact it has aluminium cabling coming into that junction/duct is a probable point of failure" - or words to that effect.
That's not too far from the problem I had where my drop wire from our over head lines terminated in an underground chamber about 100m from my property. The 100 pair cable in that junction box was aluminium going to a junction box a further 200m down the road. The 100 pair connector unit was a type used on Poles and not ideally suited to being underground and often spent 90% of the year under 3ft of water. If it were not for the fact that any time an engineer lifted the 100 pair cable out of the water you could pretty much guarantee a few lines would lose their phone lines/broadband due to the joints breaking when moved, BTOR wouldn't have touched our cabling either.
Whilst they didn't remove the aluminum, they did re-wire the whole 100 pair and enclose it in a more suitably water resistant junction box. That at least made the 'mean time to failures' go out to 3-4 years instead of 3-4 months !! When ever it failed, the local engineers would always go check that junction box first and 9/10 it was inside that box.
So push for line is noisy, poorly functions on voice at times and oh by the way, broadband keeps dropping out too. eg. don't push too much on the "it's got aluminum in it, that's the fault"