In other words, use the bull's eye bubble level to get you within range, and then use a 2-axis or 3-axis bubble level set to fine tune?
AFAIK yes - but maybe this is approaching perfection in the world of photography.
I guess my point is that the bulls eyes bubbles are NOT very accurate or sensitive even if they are right on.
Transits (older ones) typically used two large horizontal bubbles with very large radii (short radii are less sensitive); levels typically used one bubble and the instrument was rotated 90 degrees to level the other way. Even if the bubble was not "spot on", by adjusting the instrument so that the bubble stayed in the same position in its "tube", no matter what the rotation, it was very accurate.
I don't know how convenient a level would be in the field (not too), and where one would position it.
I once checked a house on which the builder had used a string level to set the foundations (it clips to a stringline). The house was 40 feet long and was out of level by eight inches from one end to the other. And he was puzzled as to why the bubble wasn't accurate.
He had to re-build the foundation.