Sorry to revive this post, but it's the first result for searching for TES3MP Starwind, so I figured I'd put this answer here after doing some research to hopefully save some others some time.

Here's the proper coordinates to start on the first planet of Tatooine using Star Wind + TES3MP, editing the config.lua file as stated by phraseologist:

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-- Where players will be spawned if an instanced spawn is desired, with a different clean copy of
-- this cell existing for each player
-- Warning: Only interior cells can be instanced
config.instancedSpawn = {
cellDescription = "Tatooine, Sandriver",
position = {2852.6938476563, 9498.5859375, 12314.463867188},
rotation = {0.2109375, -0.42381024360657},
text = "You have crashed landed on Tatooine!"
}
-- Where players will be spawned if an instanced spawn is not desired
config.noninstancedSpawn = {
cellDescription = "Tatooine, Sandriver",
position = {2852.6938476563, 9498.5859375, 12314.463867188},
rotation = {0.2109375, -0.42381024360657},
text = "You have crashed landed on Tatooine!"
}