Yes. What we did, as the company wanted value asap, is port feature to feature and db tables that supported those features. We used vue for the front end and laravel as an API. This allowed injecting new "pages" into existing Wordpress themed pages. In the vue pages vue router caught the required routes others wise Wordpress handled them as default.
As it progressed we finally where able to set the domain to a new server that was 100% vue.
We decided on vue frontend mainly because we could inject via components new and re-done features that only communicated with laravel. Utilizing props we passed in the user information as needed. We then just copy and pasted with minor updates (using vuex versus 100% component scoped data and obviously user info). So updating the vue full app wasn't a huge deal/time.
We also killed two birds with one stone in our situation as some of the users wanted API access anyways for certain content. This obviously was in place already with out dublication as the vue app also utilized authentication via oauth style (passport) and cors. So users just grabbed a key pair and hit end points as needed.
It was still a pain as your maintaining one app while building another so you end up switching a lot, which is more of a mindset issue then anything. Like switching from php to JavaScript.
Other then that it was seemless and very little issues. The client was happy to see continues progress and end users had 0 interruptions except that some routes changed that they favorited and forcing setting new passwords when the final switch was complete (messages where displayed but still...).