Hi Ard,
Short story: No, TE is not a concern for RT drivers, at least not upstream [1].
Long story: Even if a downstream added support for RT relocation itself, TE images are loaded misaligned by DxeCore, because it lacks a (terrible) workaround as done in PeiCore [2]. It doesn’t look like anyone tried to use them in DXE at all.
Best regards,
Marvin
[1] https://github.com/tianocore/edk2/blob/11f0014c0e3046e3762eac420b760091d0cdc063/MdePkg/Library/BasePeCoffLib/BasePeCoff.c#L1759
[2] https://github.com/tianocore/edk2/blob/11f0014c0e3046e3762eac420b760091d0cdc063/MdeModulePkg/Core/Pei/Image/Image.c#L412