I have soft proofed two photos using my print service's icc profile. When I get to the LightRoom Print module I am using the "Print to:" JPEG FILE option. There is an option in the Print module's Color Management panel to apply the icc profile for a second time. Do I need to do this as I have already applied the profile in the develop module? I'm worried that a 2nd application might introduce unwanted effects.
The develop module has a default color space of Pro Photo RGB. Some customers use the Adobe Standard profile or a camera/custom profile to give a consistent “look” on the monitor. You will need to select the ICC profile in the print job tab when exporting to jpeg. That will ensure it is embedded in the jpeg files you send to the print lab, otherwise you will be sending them sRGB photos.