getDocumentPixmap causes lag on large canvas

[F-know]

When using the Generator.prototype.getDocumentPixmap function on a large canvas (e.g., 2048x2048 pixels), I noticed that Photoshop becomes unresponsive for several seconds, making it impossible to draw. The duration of this lag is directly proportional to the size of the canvas. During this lag, both my CPU and GPU usage are very low. Is there a way to reduce this lag time without changing the canvas size? Thank you.