It's unlikely that this is going to be picked up by Blesta directly due to the real lack of demand, and clearly from the lack of updates here on the forum it's unlikely to be picked up by a community member so you may wish to look for a developer using other sites like UpWork, Freelance etc. Have you also checked the 'Find a Developer' section on the site? This can be found along at https://www.blesta.com/development/
In addition the Blesta team can also undertake custom work if you sponsor the development, have you tried reaching out to them along at https://www.blesta.com/about/#contact?
Ultimately if you're searching for custom work to be done it's down to you to source/find a developer, the community isn't going to find one for you.