Extend Ultimate Member Plugin Functionality

Howdy friends! I'm looking for an experienced WordPress developer who knows and understands how Ultimate Member plugin works and could develop additional functionality for our community website. We need a functionality that would allow us to send bulk private messages to our members so we could easily send announcements and share news with our community. How it should work: 1) Admin should have a separate page (either in backend or front end) where he can type a message and hit sent. 2) Once the message is sent all members will be notified via Ultimate Member that they have a new message from admin (ultimate member usually sends email and on-site notification about new private message. 3) Members should be able to see a message in their profile in Messages tab. See how Private Messaging works on Ultimate Member here: [login to view URL] 4) Admin should be able to use a variable, for example, Hey {frst_name} to dynamically insert the first name of the recipient in the message body. 5) To avoid server load and surcharge of users login in and checking their inbox, I suggest sending the bulk private message in batches over a period of time. Oct. 24th deadline