The phrase "although moderately" is correct and usable in written English.
It can be used to introduce a contrasting idea or qualification, often in discussions about opinions, conditions, or evaluations.
Example: "The project was successful, although moderately so, as there were several areas that needed improvement."
Alternatives: "even if somewhat" or "albeit to a degree".
I have also sinned in the realm of drama, although moderately.
Three were stable, two species were uncertain and only the grey long-eared bat (Plecotus austriacus) declined, although moderately.
Bertie, although moderately stout, would like to make it clear that he has never had anything to do with bankers.
The activity increased with trans-membrane flow rate for the three membranes, although moderately with the 25 nm pore membrane.
The sex scenes, although moderately heated, have none of the biting and clawing urgency of uncontrollable animal heat.
Although moderately drought tolerant, lodgepole pine is associated with climates of relatively cold nighttime and spring temperatures, and its frost-tolerant seedlings may provide competitive advantage over other conifers (e.g., Douglas-fir) in these areas (Lotan and Critchfield 1990, Coops et al. 2005).
Service also improved, although only moderately.
Arborio rice pudding shot with bits of dried apricot was heavy, as this dish can be, although only moderately sweet.
The condensed pyrrolo-triazolo-pyrimidines, although only moderately active, can be used as model for the design of DNA-interactive compounds.
Although the moderately strong correlation coefficients did indicate some degree of overlap between the skills and abilities being assessed by the three tasks, the correlations were not strong enough to suggest that they were assessing exactly the same things.
Although only moderately successful in America, Letters was immediately popular in Europe upon its publication in 1782.
