There is an article in Natural medical journal (not sure it is a real journal, but it does have references) talking about different forms of quercetin including isoquercetin. Isoquercetin is available from a reliable company integrated therapeutics (not a household name because I believe they only sell directly to docs).
The article you mention is here.
"Comparative pharmacokinetics in humans demonstrates that the absorption of quercetin, isoquercetin, and rutin in humans involves different mechanisms. Rutin has the lowest relative bioavailability and is not significantly absorbed before 2 hours, showing peak plasma concentrations at 6 hours after intake. Metabolites of isoquercetin appear within 30 minutes in the systemic circulation; a rapid rise to a peak at 30 minutes is seen with isoquercetin, suggesting active or enhanced transport; quercetin aglycone exhibits a slow rise to a plateau at 1–4 hours, indicating absorption by passive diffusion from the stomach and through the intestines.41,42"
The superior bio-a of EMIQ, giving improved bio-a of resveratrol, plus the fact that querectin delays the attachment to detox molecules that metabolize resveratrol is most beneficial. I source mine here as EnduraQ (EMIQ) due to the favorable price, dose, and bioavailability (17.5x quercetin).
Info also here. "Since quercetin is nearly insoluble in water (<0.1 g/100 mL at 21 °C), enzymatic glucosyl conjugation has been performed to enhance its water solubility [7, 8]. Enzymatically modified isoquercitrin (EMIQ) (Fig. 1) is one of water soluble glucoside derivatives of quercetin. EMIQ is produced from rutin via enzymatic hydrolysis, which removes the rhamnosyl group, followed by treatment of the product with glycosyltransferase in the presence of dextrin to add glucose residues. The bioavailability of EMIQ, which is absorbed as quercetin and metabolized like rutin, is about 17-fold greater than that of quercetin [8]. It is therefore reasonable to expect considerably greater health benefits with EMIQ. In Japan, EMIQ is approved as a food additive [9], and the U.S. FDA concluded that EMIQ is generally regarded as safe (GRAS) for use as an antioxidant."
"Another possible mechanism is related to the effects of rutin on mitochondria. Recent studies have suggested that quercetin exerts its beneficial effects independently of its antioxidant activity. Thus, quercetinmodulates pathways related to mitochondria biogenesis, elevation of mitochondria membrane potential, oxidative respiration and ATP anabolism, and intra-mitochondrial redox status [26]."
And given this,"Eventually all resveratrol is conjugated with sulfate or glucuronate as it passes through the liver, but the simulataneous injestion of querectin or peperine delays the liver conjugation and allows for more immediately available free-unbound resveratrol in the blood circulation." I suggest it is likely more beneficial to delay and keep free Resveratrol in the blood straight away after assimilation, rather than to go to extremes to try to modify P450 enzyme activity (which will occur regardless at a point). Doing both may be ideal, but just the thought of consuming grapefruit juice and coffee together sounds a form of acid indigestion torture! Beyond that, as has been described, there seems to be a very vague story regarding just which CPY enzymes we should be inhibiting to attempt to delay resveratrol metabolism. From what I've read, focusing solely on CPY2A1 as a way to do this seems quite an oversimplification, to say the least. It appears Resveratrol's P450 metabolism is considerably more complicated, involving many enzymes.
Bottom line, who knew resveratrol's assimilation and metabolism could be so complicated and multifaceted?