Here is a data point... On my 10" MF, when it was in the garage, and ambient was > 20 degree C, I could reach 110 without a lot of struggle. Below that, it was constant on and problematic although I was well below the rated PSU wattage. I don't print a lot of ABS anymore so it isn't much of an issue and the printer is inside where 22 C is pretty close to the norm. Heats to PLA 70 deg by the time the extruder is hot. I like that ABL lets the bed warm thoroughly while probing. My sensor is mounted below the heater PCB per the directions. I use a cardboard spacer which doesn't reflect heat upward as I'd like. I tried (briefly) a silicon potholder and found it the same as cardboard. So now we use the potholder in the kitchen. I've wondered: How do Al beds do? I occasionally come across a slice of Al that would work but I think about adhesion. The sensor below doesn't really reflect what is actually going on at the glass surface. Particularly hardware store glass like I run. I always figured a drop in thermal transmission through the glass so the extra time lets the temperature penetrate and as glass is an insulator this can take some time vs. what the probe reads.

IIRC, some, like maybe clough42, don't use a heated bed for PLA? I also recall 200mm bridges from his masterpiece, so I aspire.

Not a 12in so YMMV.