I haven't tried any of these tools. I have always placed the blade on the boot, marked the position, removed the blade, and then drilled it. (I've also tried using very thin diameter self-tapping screws instead of drilling a pilot hole - but I'm not good enough at keeping them at right angles to do a good job, and am not certain that even would work very well if I could.)
Or I did it by eye, using a hand-powered drill. But that isn't what I want - I can more or less judge by eye the center of the hole, but it is much harder to judge the center of the countersink bevel by eye. (Perhaps a "push drill" would be usable with more accuracy than the crank powered drills I own.) I've never had an electric drill with a thin enough chuck. I have a Dremel tool with a thin enough chuck, but the tool handle still gets in the way. Besides the Dremel can only drive very thin drill bits, so one might have to make a pilot hole to center a bigger pilot hole, which I'm not sure would be accurate enough.
I've bought tools a number of times that I thought would do things that I wanted to do, and didn't. So I'm reluctant to buy any of these, especially if they are in packages, or I have to order them by mail or over the Internet. so I can't test the retractability, and how much of the drill bit is exposed,
SO: If you could give me the exact brand and model # of a retractable sleeve center adapter, that meets all of the following:
It can take large enough drill bits to do the job.
It can hold the bit with a small enough length of exposed drill bit that it won't drill too deep, but can be adjusted to the desired screw depth.
It has a strong enough spring on the retractable sleeve to force the drill to stay at right angles.
It is thin enough not to get in the way of the blade..
It has a round shaft that will fit most drills.
It is sturdy enough to do the job.
It isn't outrageously expensive.
then I might buy it - though even then there might not work because I haven't thought of something that is needed. Otherwise, I'm reluctant to keep buying things that don't quite work.
I went to a Home Depot to look for "center drills". There were several. They were in packages, except for one. It didn't have a retractable sleeve - so I guess you would need to do as I suggested - drill in many stages, with different lengths of the bit protruding, the first of which would barely touch the surface, and, that wouldn't be as neat, or as accurate. I couldn't tell if the ones that were in packages, that looked somewhat like
https://www.homedepot.com/p/Bosch-1-4-in-Steel-Clic-Change-Self-Centering-Drill-Bit-Set-3-Piece-CC2430/205391771have retractable sleeves.
(That one only has very thin drill bits too. And it has a "quick change" shaft, not the round shaft my drills are designed to drive, so I would need another adapter - which itself might need to be thin enough.)
And even if they did have a retractable sleeve, I don't know if the spring tension would be strong enough to force the drill to stay at right angles to the surface.
As far as thin drills with thin beveled chucks, there are drills like that deigned for hobby or medical use, but I don't know if they have enough power, or are sturdy enough, and which do not have retractable sleeves, e.g.,
https://nueby.com/product/mini-electric-drillhttps://www.amazon.com/bnionlkm-Magnetic-20degree-Pivoting-Accessing/dp/B09JZFNC19https://www.ebay.com/itm/165024106027https://www.ramotrading.com/products/foredom-flexade-34-long-flexible-shaft?variant=39701253816402https://www.amazon.com/DEWALT-Adaptor-Stubby-12-Inch-DWAMRASETFT/dp/B08K9C5MCDThere are lots of hand hobby or surgical tools that MIGHT sort of work, but with the same limitations, e.g.,
https://www.amazon.com/Vise-Hand-Drill-Jewelry-Making/dp/B098CF3VMM (not electric)
https://www.micromark.com/Premier-Elite-Moore-Surgical-Hand-Drill Mod Edit: Removed referral coding in links.