Thanks for this. I just ordered a copy. Here are two other gay novels I've read and recommend that have WWI as the backdrop:
THE WORLD AND ALL THAT IT HOLDS by Aleksandar Hemon (2023) A story of the love of two men and the horrors of war.
ALEC by William di Canzio (2021) which is an imagining of what happens to the lovers from MAURICE. A sort-of sequel. Deeply romantic.