Yes.Thank you both for the fast response.
Yes I noticed that in a earlier post but because that twrp-3.5.2-renoir-Nebrassy.img is listed as unofficial, I thought it wasn't safe to use yet.
So it looks like to keep my phone updated from now on, I need to explore how to install this twrp and use the phone's built-in Updater app?
I think it may be as simple as to copy the ROM on your phone, fastboot boot twrp.img, and then install the zip, but I am not an expert, I am still learning. Please double check just in case.