Simulink Mask Editor - Dynamic Adjustment of User Input Value

Hello everybody, I hope you are fine and have good wealth.

I am using the mask editor to create costum libraries and would like to adapt (recalculate) the value of a user input, depending on certain hardware conditions. In other words, the user enters a value for a desired switching frequency, which is checked to see whether it can also be implemented in the hardware. The value is then changed accordingly and should then be accepted from the user as the new value for the switching frequency. I would also like to prompt the user with this changed value in a popup message box. I understand, I have to use some kind of Dynamic Mask Dialog, with a callback function to check and manipulate the desired user value.

1. Can someone please give me a tip on which implementation approach would be appropriate?

2. Is it possible to program a popup message box in the Mask Editor?

Thanks again to everybody for your valuable help and with best wishes,

Lars