How to compare algorithms for automated insulin delivery using different sensors?

Recent caution has been advised against comparing automatic insulin delivery (AID) systems that use different sensors. 1,2While the same two AID systems (Tandem Control IQ (CoIQ) and Minimed 780 G (MM780G)) have shown clear differences in time in range (TIR) outcomes, studies report no clinically relevant difference in HbA1c 3,4 or only minimal changes in HbA1c and TIR. 5,6A simplified overview of these four studies is presented in Table 1.Of note, all TIR values are numerically higher in persons using MM780G (from 2.4% to 7.0% points), but all HbA1c values are minimally lower in persons using CoIQ (about 0.3% points).Tree studies 3,4,6 provide information on sensor mean glucose or glucose monitoring indicator (GMI) 7 over a 2-week period and HbA1c, which can be translated into estimated p-glucose from the ADAG equation (A1c-derived average glucose). 8though this indirect approach contains several pitfalls, the result may indicate differences in sensor performances.Specifically, the Dexcom sensor connected to CoIQ appears to measure glucose levels higher than the Guardian sensor connected to the MM780G.This observation aligns with a recent small-scale study in which persons used both sensors simultaneously, reporting a slight positive bias for the Dexcom and a negative bias for the Guardian sensor when compared to self-monitored blood glucose. 9This discrepancy between sensor-driven and sensor-independent glycaemic metrics indicates the influence of varying study populations and sensor performance across brands.However, does this necessarily imply that the insulin delivery algorithm and continuous glucose monitoring (CGM) data hold no significance?Consider a scenario in which an insulin pump using algorithm