[Maria-developers] Myisam-repair-threads question

Hi Im currently doing a reload process to an empty myisam table with 4 indexes on Maria db 10 1 13 on win64 and noted that on the last step that the status reports that its using repair to rebuild the table. Myisam-repair-threads remain the default but noted that many threads were running .im not sure if all of them were for repair. Is there any recommendation which i should take using the referred setting with a greater value?would setting it to zero make maridb decide which is there best value? Would the indexes get too much fragmented ? Thanks!