This has been on our radar to provide as an option. We've opened up an issue for this here. We've also noted that there is a corrected version of 214, i.e.214.1, and opened an issue to include this database version too. But in the interim, the following set of commands should help set up the GTDB files for import, and any further curation you'd like to do with RESCRIPt:
Grab taxonomy from FASTA header
The following command will extract the taxonomy, remove >, then replace the space before d__ with a tab, and then removes the [] ... annotations that occur after the taxonomy. Finally, write output to tsv file.
egrep '^>' ssu_all_r214.fna | tr -d '>' | sed 's/ d__/\td__/' | sed 's/\[.*//' > ssu_all_r214_taxonomy.tsv
I just wanted to let everyone know that we now support downloading GTDB reference data that has not been clustered into species representatives. Please see the updated tutorial. Just install the latest version of RESCRIPt.