At the end of the 2015–16 season Lavin would take part in his fourth county championships with Cheshire. He had another excellent tournament at the 2016 Bill Beaumont Cup helping his county to their first final in 14 years, and although they lost 13–35 to a very strong Cornwall side, Lavin proved to be one of the best players in the competition, with his personal tally of 49 points (including 3 tries) making him the top points scorer. The 2016–17 season was an outstanding one for Lavin who finished top scorer in National League 2 North with 378 points, including 23 tries, in a Caldy side that stormed to the league title and promotion to National League 1 – the highest level the club has ever reached. He was also called up for Cheshire for the 2017 Bill Beaumont Cup but experienced a disappointing championships as his county failed to reach the final after losing 2 of their 3 pool games. The final highlight of an excellent season was Lavin's call up to the England Counties XV for their tour of Spain. He started the first game of the tour, kicking 12 points as Counties convincingly beat Euskarians 61–19 in San Sebastián. He also featured in the second game against Spain in Guadalajara, which Counties won 45–28.
