Of course I have, I only write about the things I use or do, unlike some authors who's allegences and favourite methods/baits change on an almost weekly basis.
I originally started using flattened disc shaped baits, to try to make my bait sit on top of silkweed, I then used the same bait on clear gravel patches and noticed a remarkable increase in positive takes.
I now only use round baits on relatively virgin waters, where I may be baiting heavily for extended periods, so I get my bait made for me.
Nashys F1 was available in oblong 15mm x 10mm to fieldtesters, but I'm unsure if this is available to the public, other than that, if you want it made then I think you are restricted to round baits.
If this is the case then just half or quarter them.