I haven't looked at the specific CoQ10 studies you link, but I've looked at a number of them. What jumped out in those is that the supplement being studied was CoQ10, not quercetin, a more bioavailable version. No idea if that might have changed any results, but there it is. It's not at all clear whether either of these is better at passing the BBB.

Given that they were investigating CoQ10, which is typically used to replace a deficiency in the ECT caused by statins, I can't help but wonder what the interplay might be with lipophilic statins. If I were a MD (I'm very much not) step one would be to get those patients switched off those to either a different statin or an alternate therapy just out of caution.