I would like you to improve the feature that can be changed the display format as same as Excel's when inputting the value to the edit form in PowerApps.
For instance, if I enter the value  and press the [Tab] key, it will be the form in which the digit separator [54,321] is immediately reflected. As for the function of Excel, you can easily change the display format by right-clicking on the cell and selecting [Display format] > [Numerical], and clicking [Use 1000 separator]. In PowerApps form, there is no function available even if you try to set the display format by entering a numeric expression.
In the meantime, we made the separator possible by setting the display format on the label as numeric expression and display/hide the label to separate the digits. ( to [54,321]) In the future, if users will be able to change the display format with simple operation, it gives us a great experience to take advantage of data as well.
Therefore, I hope PowerApps feature will be able to change the display format by operating intuitively as same as the Excel's.