Yes, Ysart weights with a thistle millefiori design are definitely interesting and I suspect a challenge to make (but not as rare your thistle in powdered glass
).
By the way nobody seems to have mentioned it here but Paul Ysart is known to have made thistle weights using the frit method during the Harland period. Colin Mahoney mentions them in his book 'Masterworks: the paperweights of Paul Ysart' at p. 116 and shows a picture of one with an H cane.
I do not know how rare these are but in nearly 10 years of collecting I have never seen one in the flesh.
SophieB