Precision work on a TAIG needs very well ground bits as fine feeds need even more ‚fine’ cutting edges. A fine cutting edge means low cutting forces, leading to small deflections of the TAIG components. Low cutting forces are desirable in bigger machines anyhow.
After several years of constant use of my TAIG lathe I had a collection of over 30 odd shaped tool bits; these were ground from square ¼“ or 6 or 8 or 10mm blanks. The main nuisance was the ground rake angle which allowed about 10 re-grinds; after this the tool tip had to be cut off and to be ground anew.
Some day I made a parting tool bit holder for 1.5 x 5 mm blanks mounted in a toolpost with an 11° inclined toolbit seat. The (known) idea was to adjust the tool tip height by shifting the toolbit - with a ratio of 1:5.
An important benefit is the ‚rake without grinding’. You just ‚shave’ the 2 faces of the tool tip with the bench grinder. For 100 grindings you use just 10 mm of the blank.