Can NIH-SIP alumni give advice on the application?

I know NIH is a crapshoot for anyone who doesn’t have connections (aka me) but I just wrote my cover letter and I was wondering if any NIH-SIP alumni could give me advice on it (over PM) or on applying in general. I wish I found out about it in November, because I hear it’s rolling admissions, but I suppose it can’t be helped. Thank you!