ABSOLUTELY RIGHT! No-one should do so 
This is never a good way trying to fix a problem, if there is a genuine problem with darktables CL code not calculating required memory correctly we must identify the problem and fix it. We did so many - many times over the last years.
I know we have a strict “be kind” policy on this forum and i hope i don’t offend you @Terry. Just to let you know, we have had loads of issues related to exactly this problem, people following such advice, everything seemed to be fine and suddenly BANG, off it goes.
I fully understand, people new to darktable want the best performance they can get. They follow users advice and are very happy with resources set to maximum for the first weeks and never have a problem. Then they start to get into dt, see some videos from our mask magician and try to reproduce. They get into d&s module and start dragging the sliders - we all did so i think. Whow - that looks really cool but it takes so long … Crash happening.
What will the new user do? Any chance he/she remembers that setting in preferences done two months ago could be the culprit? Or running dt proudly and wanting to share some images? Open Firefox with some windows for the email, chat … and suddenly dt bangs again. Same story, same problem, other symptom
I have been working on dt OpenCL code for some years now and thus worked on a load - and did a fix - of dt github issues. Leaving amd, rolling distros and windows issues aside, taking too much of cl memory is on the very top of the list.
I would appreciate it a lot if you and all experienced users would give advice: 1. Try to keep with preferences defaults 2. Suggest to read the manual on such tricky topics.
BTW: the mentioned issues with details and mask blending have been fixed in 4.6