, It happens a lot, and its not really considered a big deal. I lost mine back before i retired and didnt even worry about it, when i got to the airport to leave, i just asked the friendly Qatar airways lady to give me another, she was happy to do so.
The requirements are listed on the UK gov website, they have been changed since I last applied. After a second look it seems that a simple copy of visa will be enough.
As a retiree, how do people provide the Name and address/and or residency evidence , asked for in the British passport application ??. I dont seem to fit the bill for any of the examples shown.
What has that got to do with Immigration, which is what the OP was asking. Also your assertion that people will have trouble is obviously not borne out by the fact that no-one has reported having any trouble.