It did for me - banked discounts and referreal credits carried over to the Visible+ Pro after I received an email from Visible stating that fact yesterday. I have the Save15 for another 21 months.
Initiate the switch, and verify Next months payment breakdown before actually submitting the request. Keep screen captures of everything in the event something goes wrong and keep the email if you've received it.
The switch went smoothly for me despite an obvious error in next month's preview payment and a "red flag" email message indicating they'd charged me for the new plan (no charge occurred). After submitting the switch, everything shows as it should with Visible+ Pro, prior discount and referral credits still banked. As is common with Visible, YMMV so keep receipts of everything.
