Yes, i run my own firm, and my honesty and integrity are an essential constituent part of my business. i am not going to lose it all for a petty claim, and certainly not self-inflict a revenue investigation!!

Back to the OP point, i put all business stuff through the business, and would use redemptions for private stuff,or any marginal stuff eg when i take "the staff, ie Mrs A" with me to drum up work in Cyprus for a few weeks, when I might not normally be there . i think that it is the point the OP is after, when the marginal costs come into play.

i run with the view that after costs what is left is the profits that i pay tax on. i therefore always put all properly incurred costs throughthe business to reduce my tax bill. i use the "perks" for me.

Hope that makes sense.