I'm not sure it's way more work than Blazblue (quantity wise) but it's probably more work time for them internally. Since they had no animator in the studio for Blazblue, they draw keyframes on paper, modeled the character in black and white with shadows and reproduced the keyframe with the 3D model. Once it was done they were sending the 3D models keyframes to China (or was it Korea?) in an outsourcing company that was doing the sprites for them and the in-between frames plus colors.
With Xrd they are doing the same exact process that they are very used to, except they have to build a better 3D model first which takes more time for sure... But once it's done, they can speed up the process and skip the sprite creation part since they only have to clean some shadows here and there.
I don't know what is more time consuming for them, probably Xrd since they have to do everything themselves... But it may be less work overall? I'm interested if you can answer a bit on this one Shaowebb.
Anyway Xrd is really impressive, Revelator even more.
Believe me, I'm no expert on this style as I'm just now toying with it, but I'd say that the GG Xrd method is without a doubt FAR more work than BB if BB is outsourcing frame art using 3d model keyframing.
You see making a 3d model isn't rough. Sculpting is fast and easy thanks to stuff like Zbrush and mudbox. Heck their are even autoriggers that can help shave some work too ( I use them when I can.) but you will still have to paint muscle weights to make the body's anatomy bend and flex properly. Then theirs still stuff like putting constraints and messing around with them on the attached costume pieces of their outfit and adjusting soft and rigid binds on them so the correct areas squash and stretch or dont.
^That stuff has to be done on EVERY model on any 3d work to animate it with the exception of using Zbrush's zspheres to just sort of pose your model without actually having anything proper to animate it...it may work for just setting up keyframes though but losing the ability to scrub a timeline to adjust a pose and having to use history to find those points isn't very alluring.
Anyhow all that modeling stuff has to be done, and aside from muscle weights it takes some work. If you are JUST posing your model to setup keyframes and then tracing those screenshots of those poses to speed up a 3rd party animation companies hand drawn pipeline then its super easy and not a lot of work even if you still have to wait for them to finish.
The GGXrd method is FAR more work than that. For starters unwrapping bodyparts themselves requires FAR more UV seams. Before youd just unwrap an arm as one piece and texture it, but for their method minimal seams is NOT the goal like a normal UV map. They are using the seams themselves to draw in details since unspecified black textures on a UV map are rendered more like vectors than rasters at zero detail loss if your UV is showing any. Black space is generally just negative space on your map's layout but if any is within the area of a map it'll render actual black lines on it based on coordinates like a vector instead of based on pixels like a raster.
Essentially they used a reverse method of texturing. Instead of painting patterns and gradients and fine line details by hand like normal then trying to keep the amount of seams on the model hidden and minimal so you couldn't see where patterns began and ended they used a different approach. They made the seams as visible as possible and used solid blocks of color within them and just used additional maps to tint those colors more or less based on lighting in real time.
This meant everything changed. Lights had to be carefully scripted at all times, new maps had to be painted for every frame's shading to keep it under control and to only generate the appropriate shadows as light sources move around them (i'm thinking they abused ambient occlusion mapping here), and they even had to be extremely delicate on how they setup depth maps too to control the falloff of light so it was sharp and anime like still.
All that before all the bones and controllers and frame by frame animation and manipulation of every joint on their incredibly high bone/joint count models. Heck they even use 3 sided polygons because they make smoother seam edges on UV maps than ones using 4 sided polygons.
Fun fact...I'd already talked to Q and said if rendering my models in my project ate up too much ram or hurt it online someday in alpha testing I'd just render the frames of animation out as PNG files and turn the damned thing into a sprite based game using PNG's of models to create the sprites. I'd still be able to use depth map techniques on those for shading/lighting in realtime as such tools like Sprite lamp prove anyhow. Neat to hear BB may have done something sorta like that in modeling with the intention of using those models in 2d. Given the amount of morph/squash and stretch they do it was probably easier to outsource for 2d hand drawn than to model 3d for those kind of animations and render them. That shit takes extra models and effort (as Millia's hair has proven in modeling exhibitions).
TLDR
If BB just made models, screenshotted them for keyframes and sent those off to 3rd parties to use to help them draw 2d stuff then its faaaaaaaaar easier than the uber modeling requires to make the stuff in GG Xrd between its highly complex bones, controllers, shaders, complicated UV maps and other different features. The amount of internal time it'd take to make the GG Xrd style stuff is pretty damned huge. 2d is simple...you just have to do each frame by hand. Considering they had to do the equivalent of that anyway to get the shadows to appear right and all the model squash stretch in GG Xrd its far easier to have just drawn it. Likely faster as well considering all the maps they did may have made each character nearly double the amount of time to animate in 3d than had they just made them in 2d though 2d sprites may take more memory and cause longer load times as well as possibly not stood the test of time as graphics and resolutions continue to increase.