wrong place to aske. The ltr is handelend totally independent from immigration. Extreme happy with that. Have a look at the boi ( board of investments) website. Look for ltr and all the information is there. A telephonenumber is mentioned and the people who take up the phone aard extremely helpfull!
yes can be submitted later. I did that because the requirement was that the health insurance need to have a validity of, i believe seven months. I had alreadya yearly health insurance but the expirationdate was a few months after my applicationdate so needed to contact the insuranc to change the insurancedates. That took quite some times so to avoid that the handling of theapplication would be delayed you can submit the application during the time the BOI .LTR office could asked work on the application.