Congrats on your move from SharePoint to Dataverse!
The "import from excel" feature in model driven apps is powerful enough to parse text labels into option set labels, you simply need to ensure that the option set labels match the text within your excel file.
Here is an example, I have an option set with the values "Option A" and "Option B".
In my excel file, I have the following table set up:
| Name | Created On | Choice Field |
Record A | 18/08/2022 12:32 | Option A |
| Record B | | Option B |
| Record C | | |
If I import the above table, Dataverse parses it into the below:
No need for processing after import.
