Take a look at domvm [1], disclaimer: mine. It was written expressly to allow for imperative AND declarative sub-view composition using a concise, js syntax. I used Mithril for a while before needing granular redraw and concluding that MVC wasn't the way to go.

~8k min. No build tools, no dependencies. Extremely fast [2], composable, isomporphic. JSONML [3] superset template syntax. it's plain js all the way down.

[1] https://github.com/leeoniya/domvm

[2] http://leeoniya.github.io/domvm/test/bench/dbmonster/

[3] http://www.jsonml.org/