About size of apps using RxAndroid

I am considering either adding a FSM to my app or building it on RxAndroid.

What really discourages me about RxAndroid, is the oversize required by RxJava itself.

So I would like to hear your experiences in size increase in the .apk using RxAndroid as a base framework including compression with ProGuard.

(If this is not the place to ask this question, kindly let me know which is the place since the github project is not the place either https://github.com/ReactiveX/RxAndroid/issues/405)

Thanks

Update 10-12-2017: https://medium.com/googleplaydev/shrinking-apks-growing-installs-5d3fcba23ce2