A clapper box [ala shaper tool holding] is a great expedient to single point threading - provided lathe in use has quick reverse spindle arrangements. Common for lathes focused on Imperial Threads, with additional Metric gearing. Most Metric threading requires the leadscrew remain engaged.
When that is not available, cam-retracted tool holders are the answer. There are examples posted here at HMT.net, one very good one by Thehomeengineer IIRC.

Besides more rapid threading, reduced wear on leadscrews of cross slide, or tedious compensation for backlash in reading feed dial make them worthwhile. Another unsung benefit happens when re-pointing tool bit is needed, making pickup simpler.