The play covers mostly Brooke's time prior to the First World War - his relationships (particularly at Cambridge) and loves., his travels and poems. Personally, I don't think the script was particularly strong and the cast, for all their acting ability, seemed to be reciting the lines rather than speaking them from any internal thought process or reaction. The effect was to leave us, as audience, outside the performance rather than drawn into it. Some judicious blue pencil could give the cast more time to "be" their characters rather than being slaves to the lines.
p.s. If you are going to go for "proper" set and costume then try to make sure you do not make too glaring a set of mistakes - better to be representative than overtly wrong, people did not march to war in chelsea boots, vinyl suitcases were unknown, puttees were tied neatly, the poster shows a modern naval officer ... pedantic? Perhaps a little, but the spell of theatre can be easily broken and those with an interest in WWI plays are likely to also have an interest in WWI and hence some feel for the authenticity of its representation