Hey there!
I'm Daryoush, on the superb Guru team! :)
It really depends on personal preference and what you would like customers to see, however in most cases, it is not important, unless you are using carrier calculated rates - which would not be case with a dropshipping website.
On the other hand, with manual shipping rates, the "Shipping origin" address in "Settings" -> "Shipping" does not affect any of the rates. Even if you are dropshipping, mostly from vendors in China, the admin allows for one shipping address, so you could enter your own address or a PO Box, because this should be the same address customers will use for returning and exchanging products.
I hope this helps! Please feel free to give us a call or start a live chat at any time, we are open 24/7 for your convenience and always happy to help!
Cheers,
Daryoush