I forgot to update this support request.
For others who might want to know:
1) Currently the only way to delete rows from the history is to delete them from the database. The history is stored in Options. The key to search for is ‘ctf_tax_history_’.
2) There is an oversight in the JS file that accompanies this plugin. The oversight prevents the Offset form field from reactivating after a conversion has completed. To fix this,
a) find the file custom-fields-to-taxonomies/js/ctf_tax.js
b) scroll to the bottom of the file and replace:
function ctf_clear() {
$ = jQuery;
$('#ctf_key').val('');
$('#ctf_tax_convert .spinner').removeClass('is-active');
$('#ctf_key').removeAttr('disabled');
$('#ctf_tax').removeAttr('disabled');
$('#start_convert').removeAttr('disabled');
$('#ctf_separate').removeAttr('disabled');
}
with
function ctf_clear() {
$ = jQuery;
$('#ctf_key').val('');
$('#ctf_tax_convert .spinner').removeClass('is-active');
$('#ctf_key').removeAttr('disabled');
$('#ctf_tax').removeAttr('disabled');
$('#ctf_offset').removeAttr('disabled');
$('#start_convert').removeAttr('disabled');
$('#ctf_separate').removeAttr('disabled');
}
The plugin developer seems to have vanished. I might fork the plugin to add a few improvements. Hopefully the original developer will come back before I do that.