Why do you find is hard to cast well from a yak? I don't find it difficult at all. First, one of the benefits of a yak is that your very stealthy; the fish don't know you're there (provided you're not banging the yak and making noise). So, you don't have to be very far away from your target.
I rarely have to make a cast longer than 30 feet -- and that's quite easy from a kayak.
When we go to The Everglades, we're withing 20-25 feet of the shoreline and catching 250 to 350 fish per trip.
Most of my clients start out 60-70 feet away and I have to convince them it's OK to get closers. Their instincts tell them they've got to make long casts to be successful. It's just not so.