Thanks Lucas!
I’ve offered these kinds of security assessments in the past, but I don’t do that anymore, unfortunately. Secure Meteor is basically my brain dump of everything I know about securing Meteor applications, and how I’d apply that knowledge during an assessment.
Sadly, I also don’t really know of any security professionals, pen testers, etc… who focus on Meteor security. I know that ^Lift Security has done a lot of work with Meteor, but they’ve also been acquired by NPM. I’m not sure how active they are in the area anymore. I’ve also seen people like Sam Sun and Juho Hietala report vulnerabilities on Meteor projects, but I’ve never worked with them, can’t personally vouch for them, and don’t even know if they’re open to new work.
TL;DR - I personally don’t know of anyone, sorry. 
