Sky employing engineers? When did they start employing engineers?
I have met many Sky fitters, to call them engineers is like calling a bin man a 'refuse disposal engineer'.
They are fitters. No more, no less. The qualifications for the job require no 'engineer' qualification, electronic or otherwise. They are given a brief (used to be 2 days) training course on how to install a Sky system. Any deviation from what they've been taught and they're usually stuck.
Maybe this is the reason they can't fix faults. And we pay them £65.00 call out charge!!
A while ago, after many (under warranty) repeated box failures I was promised that a 'Senior Engineer' from Sky would visit to finally cure my fault. The fitter had worked for them for less than a week! Previous job history? Unemployed for last six months, previously a 'roofers mate'!
Of course, there may be some good fitters employed by Sky. But engineers? I don't think so.
Regarding signal strength. If your signal is good when it rains, it's good enough. Leave it alone!