My answer to their survey -->

What, if anything, do you most _dislike_ about Firebase In-App Messaging?

Come on, have you sit a normal dev, completely new to this push notification thing and ask him to make run a simple app like the flutter firebase_messaging plugin example? For sure you did not oh dear brain dead moron that found his college degree in a Linux magazine 'Ruby special edition'.

Every-f**kin thing about that Firebase is loose end. I read all Medium articles, your utterly soporific documentation that never ends, I am actually running the flutter plugin example firebase_messaging. Nothing works or is referenced correctly: nothing. You really go blind eyes in life... you guys; right? Oh, there is a flimsy workaround in the 100th post under the Github issue number 10 thousand... lets close the crash report. If I did not change 50 meaningless lines in gradle-what-not files to make your brick-of-puke to work, I did not changed a single one.

I dream of you, looking at all those nonsense config files, with cross side eyes and some small but constant sweat, sweat that stinks piss btw, leaving your eyes because you see the end, the absolute total fuckup coming. The day where all that thick stinky shit will become beyond salvation; blurred by infinite uncontrolled and skewed complexity; your creation, your pathetic brain exposed for us all.

For sure I am not the first one to complain... your whole thing, from the first to last quark that constitute it, is irrelevant; a never ending pile of non sense. Someone with all the world contained sabotage determination would not have done lower. Thank you for making me loose hours down deep your shit show. So appreciated.

The setup is: servers, your crap-as-a-service and some mobile devices. For Christ sake, sending 100 bytes as a little [ beep beep + 'hello kitty' ] is not fucking rocket science. Yet you fuckin push it to be a grinding task ... for eternity!!!

You know what, you should invent and require another, new, useless key-value called 'Registration API Key Plugin ID Service' that we have to generate and sync on two machines, everyday, using something obscure shit like a 'Gradle terminal'. Maybe also you could deprecate another key, rename another one to make things worst and I propose to choose a new hash function that we have to compile ourselves. A good candidate would be a C buggy source code from some random Github hacker... who has injected some platform dependent SIMD code (he works on PowerPC and have not test on x64); you know, the guy you admire because he is so much more lowlife that you and has all the Pokemon on his desk. Well that guy just finished a really really rapid hash function... over GPU in a server less fashion... we have an API for it. Every new user will gain 3ms for every new key. WOW, Imagine the gain over millions of users!!! Push that in the official pipe fucktard!.. What are you waiting for? Wait, no, change the whole service name and infrastructure. Move everything to CLSG (cloud lambda service ... by Google); that is it, brilliant!

And Oh, yeah, to secure the whole void, bury the doc for the new hash under 3000 words, lost between v2, v1 and some other deprecated doc that also have 3000 and are still first result on Google. Finally I think about it, let go the doc, fuck it... a tutorial, for 'weak ass' right.
One last thing, rewrite all your tech in the latest new in house language, split everything in 'femto services' => ( one assembly operation by OS process ) and finally cramp all those in containers... Agile, for sure it has to be Agile. Users will really appreciate the improvements of your mandatory service.