Yup, exactly. Although even if I had unlimited space and size of tanks and so on, I'd probably still work to smaller enlargement factors with bigger formats. Obviously you can look at it both ways - you can use larger formats to get bigger prints for the same sort of final image quality on the paper, grain size and so on, or to get higher quality, finer grain, etc. with the same size print.

As it is, with the same enlarger I can get about 17x with a 50mm lens for 35mm, about 8x with a 100mm lens on 120, and about 5x with a 135mm lens or 4x with a 150mm on 5x4. And in all cases the biggest paper size I can either dev, wash, or dry is 20"x16", which happens to fit all those enlargement factors quite well.

Having said that, some months ago I acquired a 28mm Componon which would allow me enlargements of up to about 34x off about half of a 35mm neg, and I do hope to explore the creative possibilities of that some time with some really outrageously grainy prints. I might try pushing HP5 up to about 3200 and shooting with wider lenses than the compositions require and see if I like the results.