I have seen code where an object pointer is stored in each row of a TDataSet, and referenced by code. So skipping the question of the validity of such code, how do you support X86 and X64 bit code, especially if you use persistent TFields (use Delphi’s Form Designer RAD approach for the UI)?
For 32 bit development a TIntegerField works just fine. Compile for Win64 (the OS/X compiler still doesn’t support 64 bit code) and everything seems fine until you run the app and exercise the code to find an AV.
A NativeInt scalar type is variable depending on the word size of the CPU, but there is no equivalent TField descendant (TNativeIntField), so you are forced to choose a different TNumericField descendant depending on your target (32 or 64 bit) or one that can support both. The TLargeIntField uses a largeint (equivalent to an Int64) for internal field storage so it is the only possible choice that could support both targets and still provide design-time support. The overhead of such an approach is questionable. Otherwise, if you create the fields in code I would suggest conditional compilation using the CPUX64/CPUX86 directives.
If you need to support 64 bit targets I would also suggest development using Win64 so you don’t have to test each pathway for a 32 bit application to ensure it runs fine as a 64 bit EXE.