I used to work at a bakery/snack producer that had a 2 week shutdown for Christmas & we had the same issue (how to assess the quality of stored oil over life) – although this was some time ago & technology is likely to have progressed since then?.
From what I can recall three things that have the most effect on oxidative rancidity are temperature changes, presence of oxygen & presence of catalysts (contaminants that can promote/accelerate rancidity). So, theoretically keeping your oil at a constant temperature in a suitable covered vessel (food grade stainless steel) is less likely to accelerate rancidity than a constant heating/cooling cycling.
You can test FFA/PV to assess the % of free fatty acids & peroxidase value (assuming you have standards on your specifications to determine acceptable/unacceptable) and/or taste daily to assess the organoleptic quality. Current wisdom is that the human palate is able to detect miniscule changes in flavor (from products of oxidative rancidity) before this is detected by analytical testing, so along with your chemical testing a panel of trained tasters regularly assessing the oil flavour is a good control.
As your frying temperature will exceed temperatures required for a microbiological kill step & oil will not support microbiological growth the primary consideration would be flavor deterioration (oxidative rancidity).
Best of luck & hope you manage to save some of that oil!