With large drawing files we may experience VBA performance issues while selecting individually a large number of elements. Depending on the size and type this may take minutes until all elements are selected.
I would like to point to NamedGroup elements to help to increase performance extremely.
The idea is to add each individual element to one single NamedGroup and finally "select" this NamedGroup. 
Tests are showing…

TextTable seeds are stored in your DGNLibs. If you want to find a TextTable seed programmatically, you must...

1. Enumerate the available DGNLibs (each DGNLib is a DGN file)
2. Enumerate the models in each DGNLib
3. Test whether the model is a TextTable seed.

The TextTable seed test is simple: the DGN model must contain exactly one element, and that element must be a TextTable.  Putting that altogether, I've written an article…