Alternative to Giant D-Fuse SL Seatpost?

Hey guys, I have a 2019 Giant Revolt Advanced with the Giant D-Fuse SL seatpost. While I love this seatpost for rough gravel rides it sucks when using the Revolt as a road bike with road wheels. The seatpost rocks and back forth which is terribly inefficient for climbing. Does anyone know if I can use a non-d-fuse Giant seatpost from a TCR Advanced Pro? I know Darimo makes one for the Revolt but its over $400.

Looks like you can't, but that's from just a quick google search.  The D-Fuse also refers to its shape and the Variant seatposts look round.

Isn’t there a Comp model? How does that compare to the SL?

I think the only real option would be another giant post...just maybe the defy uses a similar but stiffer post?  

I have a zero setback D-Fuse seatpost and I feel like it is much stiffer and would be more efficient for climbing. I currently have it on my Toughroad with the standard setback seatpost on my Revolt. Considering my Toughroad has a slacker seat-tube and longer chainstays, I notice that I have improved pedaling efficiency w. that seatpost. I would consider it.