I think the only low speed needles being sent out are warranty ones. I am a dealer and as far as I know I am not getting any to hand out, only the ones I ordered.
Not everyone is having problems with the current carb. I experimented and ground my low speed needle shorter on a new .25 6 port and it works great. I have seen some other motors come with 2 lsn's before, just another tuning option for the conditions.

If you change needles I do think the needle settings will be quite a bit different.

Rex