Main North Line [8]: Full aerial coverage

During the migration to Qgis 3 I have started migrating the CWNM project to this edition and it needs a bit of work to fix up various things. Alongside this I have been doing a lot to get a full set of aerial photos for every line, although particularly the Main North Line at present. 
Alongside this is a reorganisation of resources on the different computers. The ongoing issue with aerial photos has been the large amount of disk space they consume. This creates a lot of problems on mainpc as it keeps filling up the 2 TB array.
I have therefore taken a logical step to move all the aerial photos used for maps off mainpc onto serverpc. This is going to take a while to accomplish although because many of the aerial layers are not actually loaded most of the time it will not break many projects when they get moved across.
Because Qgis 3 implements a new canvas caching function that consumes a lot more resources than previous versions I am moving towards all aerial photos being loaded “on demand” in effect by implementing layer definition files saved in each source folder so that only the aerial photos currently in use actually need to be loaded. At the same time if I forget to turn on serverpc when the project is opened, reloading a qlr file will be quite easy to do.
The core custom aerial maps for each project which are quite a small number of files will probably be kept on mainpc but I will have a look into this in more detail as I progress the migration. Hopefully it will be a long time before I have to clean up any resources on serverpc.

I have changed my mind  about rushing to migrate to Qgis 3 as it still contains significant bugs. One in particular will have a major impact on aerial photography use as it gobbles up all the resources really quickly for some sort of render caching and then freezes. So back into 2.18 again. I have decided to make the most of using serverpc to run map drawing VMs and therefore am working on an optimal keyboard layout at my workstation that lets me put serverpc’s keyboard directly in front of me while keeping mainpc’s keyboard in the same place, therefore allowing me to use both computers simultaneously for mapwork without switching the main keyboard between computers all the time.