I don't think haplotypes can be reconstructed from collapsed assemblies without the raw data (if that is what you are asking), as the collapsed may not contain information on heterozygous variants needed to reconstruct haplotypes. If the raw data are available, why not generate a new haplotype-resolved assembly from the raw data, e.g. with HiFiassm or Flye -> HapDup?
An alternative could be to phase all reads into haplotypes first using nPhase and then assemble each cluster separately using haploid assembler.
High heterozygosity is a plus in this case, because it allows for better coverage of multiple heterozygous sites.