Hello,
It is nice to hear that our tweak helped you in your specific case.
‘Wondering if that redirect snippet could be changed to actually report the URL where the errors occur in a log???’ = no it is not possible, but you may remove it and check again = it will show you errors which you had in the first message you described but without any details more. You may also try to remove the snippet and check one by one plugins you have.
Truly saying that error shows randomly so you will not be able to find the real reason (or real plugin which created such thing) quickly.
We would recommend you to keep that snippet enabled because it won’t make any issues for you but only helps in some cases which cannot be found.
Regards