Here is the part of the timeline that suggests to me he could have been in Hawaii when Lori and Tylee were there. It is my speculation only because they were at a Boise conference together then Lori is in Kauai for a month with Tylee.
Feb 2019 - CV learned Lori was going to Boise with a friend for a talk or conference; CV and his lawyers made attempts to serve Lori divorce papers and order of protection papers at the airport, a hotel, and a public event. All attempts to find Lori were unsuccessful (Fox 10 Phoenix; Post Register).
15-16 Feb 2019 – Chad attends a 2-day event in Boise and Middleton, ID. Chad Speaks at the event on Feb 16. The organizers of the event say this is the last time Chad spoke at one of their events (Event Flyer, PAP Media Statement).
Feb 2019 – CV hears that Lori is living with her brother Alex in San Tan Valley, AZ. CV then attempts to serve Lori with papers at AC’s house but that too was unsuccessful, despite the fact that both Lori & AC’s cars were in the driveway at AC’s home (Post Register).
Feb 2019 - Lori and Tylee checked into a Kauai resort after CV filed for divorce. They stayed for around a month, according to resort workers, and then returned to the mainland (EastIdahoNews).