Future LOCIs + LORs advice help!

I got waitlisted at my top choice which is a bummer but still giving me marginal hope (delusion). I already sent a pre-decision LOCI, but now feel stuck moving forward in terms of what to say in additional LOCIs.

1. Do LOCIs need to include updates to the resume? I don't have / won't have major updates to communicate to the admissions committee in terms of my job. My WE is solid, but not one where I will have a lot of new accomplishments to share. I don't want to send them updates just for the sake of it, especially if it feels forced. Has anyone navigated a situation like this?

2. I feel like I maxed out my list of strong recommenders from professional / academic experiences. I know an alumni of the school who knows me well personally and can speak to my character, etc.. I feel like I already know the answer to this, but would a recommendation like this carry any weight towards my application? Or would admissions committees view this negatively?

TLDR -- I feel like I don't have much else to say in future LOCIs without being repetitive. Is it enough to just frame it around my interest in the school, additional research I've done on the school (talking to students, professors, etc.), and how my strengths/values match the school's?