DiDrafter consist of two drafters. Of course we talk about the extended version
with 6 + 7 = 13 tiles, which are connected by at least half
a edge. The seven dragon tiles ( »Q« to »W« )
are bound to build rings, that means that there are no compact forms with the
13 tiles alone.

We take a similar approach as with the DiDom puzzle ([Logelium] DiDom)
and double the tile set. This results in a covered areas of 2 * 13 * 1 = 26
isoscale triangles.

There a many convex forms with large solutions numbers. See some examples:

The onesided version has 22 tiles including 16 dragon tiles, which force a
grid shift. This ratio of 6 : 16 leads to unusually complicated grid
patterns. Therefore the number of solutions are significant smaller compared
to the double tile set forms. The example below has only 87 solutions.

I was not able to find a solution of a convex form manually, but …

… when automatically generating all 1701 convex drafter forms with an
area of 22 units and subsequent puzzle solving 27 forms with solutions were
found. Remarkably none of these are symmetrical.