As it was possibly me who provoked this thread, I'm obliged to show a bit more…
I tried my luck with the famous tangential toolholder also, but had some difficulty with the clamping – the screw or a part of the holder always coming in conflict with the work. So I started making a Wimberley clone. The first one was mostly scrap, then they became (slowly) better… I admit that the HSS bit is not as easy to grind as for the t.t.h., but mainly because I upscaled up to 10 x 10 bits. The original W.t.h. uses a tiny (3/16" I think) bit, a size I don't even think of using!
The easiest way to make one is starting with a bit of steel, about 25 mm square and 35 mm long. Mill one side off at an angle of 20 degrees, then mill the tool slot diagonally on this side, also at 20 degrees. A vise with a rotating base helps a lot for that – or set the vise oblique on your mill table. Next is drilling a hole, in my case 10 mm, in the upper left corner of the steel block, and stop when the drill reaches the tool slot. Don't forget the holes fot the clamp screws – either just vertically or inclined so they are perpendicular to the tool slot. Finally silver solder the stem into the 10 mm bore. You can use a square one turned down to 10 mm, or say a round 12 mm, which you mill flats on after soldering.
A word again to the tool bits: I found the best method for grinding the steep primary angle is using a thick spacer on the horizontal grinder table (which usually is around axle height). The height should be so that the grinding point is between 1 and 2 o'clock on the wheel, This should result in an angle of about 28 degrees (20 for the holder, 8 for the relief).
So now some pictures:

The first two usable holders, for 10 and 6 mm bits.

The smaller, front view

A larger clone for mounting directly in a Tripan holder, with 10 mm bit
here seen from the tool bit side.
Well, enough for the moment!
Kind regards, HansR.