Is a lighter cue better for draw shots?

The answer is not simple. The short answer is: It really doesn’t matter very much. For the long answer, see the following.

In general, a lighter cue can be a little better for more draw when hitting very close to the miscue limit, since it will deliver slightly more backspin to the CB per the info on page 6 here:

TP A.30 – The effects of cue tip offset, cue weight, and cue speed on cue ball speed and spin

But this is true only if the OB is fairly close to the CB, because a lighter cue will deliver less speed to the CB, and more spin will be lost on the way to the OB.

For power draw shots where the CB is not very close to the OB, it doesn’t help to cue so close to the miscue limit per the info here:

power draw shots

and here:

draw shot physics-based advice

so the potential benefit of a lighter cue does not apply in this case.

A heavier cue can be better for draw if you can stroke it with good speed, because it will result in more CB speed with good spin at large tip offsets. So the best cue weight for draw will therefore depend on the person, per the info here:

optimal cue weight

Although, if the cue is too heavy, there is a chance for a double hit close to the miscue limit, per the info in the last paragraph of the main section here:

maximum spin possible