This is awesome! Thank you. I stumbled across the "help" page https://www.uniprot.org/help/uniref which gives a general description. I've translated the description to commands using easy-cluster and easy-linclust. Does this seem to be in accord with your steps above using the more modular implementation?
mmseqs easy-cluster proteins.fasta mmseqs_100/mmseqs2 tmp --min-seq-id 1.0 -c 1.0 --cov-mode 1 --dbtype 1
seqkit seq -m 11 mmseqs_100/mmseqs2_rep_seq.fasta > mmseqs_100/mmseqs2_rep_seq.gt11.fasta
rm -rf tmp/*
mkdir -p mmseqs_90/
mmseqs easy-linclust mmseqs_100/mmseqs2_rep_seq.gt11.fasta mmseqs_90/mmseqs2 tmp --min-seq-id 0.9 -c 0.8 --cov-mode 1 --dbtype 1
rm -rf tmp/*
mkdir -p mmseqs_50/
mmseqs easy-linclust mmseqs_90/mmseqs2_rep_seq.fasta mmseqs_50/mmseqs2 tmp --min-seq-id 0.5 -c 0.8 --cov-mode 1 --dbtype 1
rm -rf tmp/*