You reference "Turbobloat" and engines being "bloated" - which is to some extent fair. But it is maybe worth describing what that means to you - what features you consider "bloat" and which you have omitted from the Tramway project. To some the inclusion of an RPG framework may be considered bloat, for example, yet there is one present in Tramway.
I like the C++ principle of paying only for what you use.