Yes .....................do as you have planned and use this as your minor. By all means when he is there comment on look at the state of that board
" I would never do it like that, as it would now be a nightmare to do a PIR on it"
And "
"That SWA not glanded in. I know it is in a insulated CU, and they have earthed it, but I would have still glanded it for mechanical protection"
All this will show him that you like to do a professional job as such. So like the old saying goes every cloud as a silver lining, so use those rough jobs to outline the kind of job you would do. And really the bottom line is, your paying his salary and he is looking at ways to pass not fail you.