Hi @Stix_13
This looks excellent! Thank you for sharing!
I can confirm, it does come up with two buttons on Android 11, OneUI 3.1:
I have tested it out somewhat... it seems great. Does exactly what I would want it to do.
I still need to test out full functionality (calling actual people) and to test for reliability... but this seems like this first viable solution.
Thank you!
@Gorog- FYI
@DieLyn- THANKS for sharing screenshot evidence and helping confirm with this 'True Phone Dialer' app we have two separate buttons SIM1 + SIM2 also working on Android 11, UI 3.1.
This gives me half the confidence to finally upgrade to Android 11 soon and then eventually Android 12......but before that, now just need to find a replacement app for Samsung (SMS) Messages that also has two separate buttons SIM1 + SIM2 and shows the respective SIM icon beside each message sent and received in an SMS conversation.
As far as testing this 'True Phone Dialer' app, I have been using it for 1+ month and functionility, reliability and performance for both SIM1 + SIM2 is 5 stars!!....no issues (yet) as this app has never crashed or stalled on launch or during any calls (yet)....look forward to your feedback upon your further testing and personal experience....
Btw, obviously free version has ads but good news is there are options to purchase ad-free edition, which are not too pricey and could be worth it!
Finally, I must express my only concern for usage of this app is security, data privacy, GDPR, etc.....just thinking if this app collects or steals any private data such as sharing phone numbers dialed or even my two phone numbers with other third party companies that results in more telemarking calls.....but in all fairness telemarketing has always been a common problem and annoying, well atleast here in Canada!...not sure if this is a common problem in Europe....however, in all fairness I guess security, data privacy, GDPR, etc concerns is a common risk with any third party app.....so i guess pick your poison this True Phone dialer app vs default Samsung Phone Calls app
Side note: I do have to upgrade to Android 11 before April 1 2022 as my corporate IT is forcing all manged devices to be compliant else our Work profile will get deleted.....so running out of time soon to find a replacement SMS messages app and get off of Android 10, UI 2.5.
Thanks again!
Respectfully,
Your friend from Canada
I started using Textra for SMS last spring because of this issue and recommend you testing it as well. No ads, very simple to use. It has only one button for SIM selection but it changes selected by pressing it and tells clearly will Sim1 or Sim 2 be used to send the message. Phone calls on default app work similarly so I'm OK with this for now. Still would be nice if separate app would not be needed...
@Proffa- I tried Textra ...which was 'ok' for the same reason you described pressing it to change SIM.....HOWEVER I did not like the fact that in the same SMS conversation when there are sent and received messages using both SIM1 and SIM2....you cannot see which message is to and from the respective SIM1 or SIM2.....as example, please reference attached screenshot.....and for that reason I stopped using Textra.....
Still searching another SMS app that has this capability
Finally got a message back from Samsung in the Samsung App on my phone acknowledging this issue and advising it will be rectified with the next update - will be interesting to see 
Hmmm good point - although one of the issues is the SIM swapping randomly and not staying on its allocated contact?
I want the 2 Buttons back as well
