Distance between the BHs for different runs (refer to Table 1). The shortest timescales for the orbit of the secondary BH to fall under the one-pc scale separation from the central BH are observed in the adiabatic runs (top panel). Almost all the other runs that include gas cooling lead to prolonged, if present, orbital decay. The exception is run CSFSN (bottom panel), in which an encounter between the secondary BH and an overdense region of gas caused a relatively short decay time. Run CSFSNBF was stopped before 60 Myr due to computational limitations.