Trying different services its better not to rush to conclusions, no matter what. For I had cases when robust and wide-spread systems failed in resolving tasks smaller vendors cracked as nuts. Simply give it a go. The results are always very conspicuous. So, how everything is arranged in TeamDesk?
To change existing column’s type in TeamDesk you need to enter Setup mode and select column type you want to modify and press "Change Type" button.
Within TeamDesk you can easily convert Data column to another type of Data column and "formula" column to the different type of Formula column or to Data column as well.
The system will notify you in case when selected conversion is not supported or when it is not possible to convert column values to the specified type. Your data will not be modified in this case.
Skimming through TeamDesk blog site I stumbled upon one post worth mentioning: how one can use formula column and change type for data alerting you can check here.
In general, TeamDesk offers robust methods for data modification. But there is stuff to work on. The developers should pay attention to usability issue for cases it’s impossible to convert specific value(s): The system displays only the first error and one can’t figure out which record/row in the table is not correct. The system has no means for users to filter and correct values in invalid records.