Never overlook the garment sweep.
I am no slickster when it comes to speed - but from an exposed rig I manage around 1.1 to 1.15 to first shot from retention. I'd like to improve on that and try but ....... keep at it!
However, the one thing I really really always feel the need to concentrate on is the garment sweep to access the firearm ... to be able to draw at all!!
The nature of the garment makes quite a difference too - and whether it be vest or longer heavier winter shirt ........ the consistent sweep being successful is IMO paramount.
If weak hand is free then that'll be be used - and works pretty reliably but - say that hand is fending off then strong hand must do the business.
That is where I feel practice is most essential ...... with any and all garments. Do y'all practice this aspect? Dry fire routines are most helpful IMO.