Maxxis 29x2.3 on 30mm internal will work on 27.5 2018 lyrik.
Maxxis 29x2.5 on 35mm internal worked on 27.5 2018 lyrik for few days until tire stretched out. At 22 psi, it was ok at 24 psi, it rubbed. if you are running sub 20 psi, it may work.
Maxxis 29x2.5 on 30 mm internal fit/turns but with almost no clearance than on 35mm internal. Prob wont work once the tire stretches out little.
Specialized 29x2.6 on 30mm internal wont even fit.