I have a kitchen table from Room & Board that has a white quartz top. It does occasionally stain with ink, pencil, colored pencil, etc. Normally I use a homemade cleaner with water, alcohol and blue dawn. It gets everything out for me. I did have one stain from the magnet on the back of my phone case which came in contact with water. I used bar keepers friend and it came right off. I am only left with a small mark that was on the table when it was delivered (we were out of the country and someone else received the table and didn’t say anything to the delivery men). It appears to be a small ink mark. We have been able to dull it slightly, but haven’t been successful at removing it. I will try the greased lightning suggested above, and maybe diluted bleach as a last resort.

One mistake you are making in your thinking is a common one - that all granites are lumped together in one group. There are thousands of granites. Some are carefree and will not stain and can take all kitchen tasks for years and years without showing anything. In the other extreme are granites that are more stain-prone, require sealing every few months and can be etched and/or stained. My granite counters are more than 10 years old. They have not been sealed. I do not baby them, and have spilled things like wine and tomato juice on them while cooking. They look like the day they were installed. I have never in all this time grown tired of their natural beauty. Go to a stoneyard, and ask to see granites that have "low absorption rates", i.e. they are dense, and therefore won't stain. If you see a granite you like, and can't find information on its durability, get the name, and also take a photo, and post on this forum. Likely someone will have information on it.

Fsal, that poultice works pretty good for oil stains. I tried it a few years ago on my carrara (before it was properly sealed). made the paste and covered it with a moistened paper towel, and then the plastic wrap. left it for a day or two. it does draw up the oil. you may have to repeat. They also sell these poultices ready-made (search "marble poultice") for stains. ILoveMod quartz is man-made. quartzite is natural. (quartzite is made of natural quartz but it's called quartzite). as for the resin, cheaper quality quartz may use a cheaper resin/materials. The most common yellow stains on any quartz brand countertop are the following; 1) General yellowing to the entire quartz surface due to build up of salts & surfactants 2) Around under mounted sinks - due to salts & surfactants in dish soaps. High pH 3) high use & cleaned area. 4) Under coffee machines 5) under pot plants on the quartz countertop 6) under dish mats or drying mats near the sink 7) under fish tanks. All of the above allow the salts & surfactants to form and generate the quartz countertops causing the yellow or light brown staining. As you will notice that UV light does not generate dish mats, under fish tanks and also pot plants. Whilst UV light can accelerate the yellow staining to white quartz countertops. IT IS NOT THE CAUSE! (they even mention high humidity and relation to salt water as contributing!) Scroll down and read the comment from Quartz Stonecare Cleaning and Restoring Experts https://www.houzz.com/discussions/2467192/quartz-yellowing

Dawn Platinum has a ph level of 12. Oven cleaner is 13, so you've etched it. It's probably fixable with a Quartz Renew kit and an experienced technician. Absolutely not a DIY, as you've discovered with the MB. If I got this call, you'd acknowledge in writing that the top was ruined and that I couldn't make it any worse or I wouldn't come. If you didn't like the refinish, you'd owe nothing. If you did you'd owe me $1,500.00 or so, just less than replacement.