Jimbo,
Definitely you can "mod" these pumps more than any pump I know. Each one of the major components has as many as a half dozen options, which you can mix or match.
However, I don't readily know how you might outfit this with last step injection in the manner than most TM manufacturers do. Typically a pulse pump is mounted on one of the cylinders on a plunger pump. As this pump has no discrete cylinders by which you would tap a single valve port, one of those last step pulse pumps would not "fit".
Typically the reason you last step inject with a pulse pump is that your main pump and HX components are not chemically fault tolerant. SG systems used partial vacuum inlet injection because they specifically chose chemically fault tolerant components to the entire system, of which the Wanner Hydracell certainly fits, when outfitted as such (all stainless & Viton).