Hi- and Thank You!!
Is there any benefit to leaving it sit in this stage longer?
If it sets too long, the lees can have a detrimental effect on the wine.
There is a process called bantonage (check my spelling) in which, while the wine on the lees, you stir the wine regularly so the lees are stirred in well. For a wine like chardonnay, it is supposed to give the wine more depth; smooth it out some. It only works if you stir it regularly.
That being said, I would not leave it on the lees any longer than instructions say; I would just stir it well, if you want to do bantonage. When the SG has stopped dropping for 3 days in a row, go ahead and rack off lees, stabilize, degas, and clarify.
Since you are new to wine making, I'd try real hard to follow the instructions. Once you get a hang of it all, then start experimenting some. Those kit makers pretty much know what is best for their kits... they should, since they warranty them... that is if you follow the instructions.
And welcome to the forum.