So an update:
i went back to my Apple Store today to see if they could help once and all - 1st off the staff at my local Apple Store went above and beyond to sort this all, could not fault them.
i actually saw the same store member as yesterday which helped things out. He took the iPad round the back to check it out and asked several other staff to listen. There was another staff member with exactly the same iPad as me who did not have the same problem but they could do a comparison which was good. So there was no problem in getting iPad pro number 4 - they tested the new one out back straight away and said they couldn't hear anything with the new one - however both parties wanted to double check so it was decided that I'd go off for an hour+, have lunch, play around with it for a bit (as iPads when on are warmer then off iPads straight from storage) and then come back in an hr or 2 and they'd test it round the back again.
So I went back 90 minutes later and the staff took it round the back and after a while the store member that had been helping me the last couple of days said that number 4 had exactly the same problem.
so both parties were in agreement that lightning striking 4 times is just too unlikely and that one of 2 conclusions was true
- this particular batch from the uk warehouse (which all Apple stores in the uk get there stock from -so going to a different Apple Store wouldn't solve it) is faulty so a good number from the uk have the same problem but thankfully for them don't have my bat like hearing. The thing is that Apple Store don't know when new batches ship from the factory to uk warehouse so it's hard to test that theory
- considering that I have now tried a new iPad pro, mid December, early Jan and now mid Feb the chances are that all 4 iPad pros I've used are not from the same batch and the iPad pro screen click is a much wider problem.
it could be a problem with a specific factory machine or the build process in general meaning a huge number of iPad pro have or will develop this issue (perhaps all of them)
My Apple Store gave me 2 options of over the next fortnight deciding to keep or return the 3rd replacement for a full refund (I did ask if I could come back in a couple of months and try another one when in theory they'd have a new batch - they said I could try but couldn't guarantee they would be able to replace it given the time lapse)
the the only way that this may get knocked on the head if this is a common issue is to report the issue via the Apple Store/sending them corspondance, even social media like this forum and videos like the one I posted. Apple don't look into/solve issues unless a high enough percentage report it to them (which at that point they are good at solving it)
For the time being I'd suggest the following:
- try to press as lightly as possible (I am debating whether to use a screen protector or not for this reason
- keep the iPad cool when possible - the last 2 iPads I tried did not start clicking till they'd been on for an hour and that Apple staff member had been turned off for a while and cold/cool to touch - so the iPad pro may not like the heat (And I realise that my radiator in my room has a broken radiator which won't turn off so could be shoting myself in the foot) - turn iPad off rather then sleep mode when you can and store in cool location.
i Haven't decided yet if I'm going to refund or not but I think I may keep hold of it, try the above and probably replace it earlier than I usually would an iPad model (in 1-2 years time rather than my 3+ years) when hopefully by then apple would of silently solved this issue if enough people report it.