Because you don't need the chain with those as the top link loop will pivot on the bottom... Or is that too hard to understand too?
I simply extend the top link and let it float.
Agreed. But maybe you didnt read my posts. Specifically #113
https://www.tractorbynet.com/forums...ins-instead-top-link-bush-12.html#post5674966
Where I specifically said that MFG's have different ways to accomplish the same thing.
There is a difference between using chains for a toplink, and having chains on the bushhog stabilizers.
People are specifically asking about a chain for the toplink. Even citing the fact that they use a chain in lieu of a toplink on OTHER EQUIPMENT to allow flotation.
It is an acceptable practice IF NEEDED. IE: if your cutter doesnt already account for tail wheel pivoting via some other method.
What you show is "some other method" but NOT A CHAIN IN PLACE OF THE TOPLINK.
And as I said earlier.....since cutters are NOT SOLD WITH A TOPLINK.....then NO MFG's DONT OFFER A CHAIN IN PLACE OF SOMETHING THAT IS NOT PART OF THE CUTTER.
Many cutters use "some other method" to allow tailwheel to pivot so a piece of chain is not necessary.
Woods uses linkages and no chain, but still floats...

newer bushhogs uses something similar.
Some use a swinging clevis like alot of finish mowers.
And still some cheap cutters have nothing and bend the straps like this one
That second picture is the one people commonly just run a chain for a toplink. Because it is simple and easy to do.
If you replace the lower bolts with shoulder bolts, or a bolt and locknut that isnt torqued real tight, or a castle nut and cotter pin, etc.....that allows the cutter's a-frame to rotate. THEN you can remove the straps that are all bent up on the cutter and replace them with chain.
At the end of the day, there is more than one way to accomplish the same end goal. And I really wouldnt point to one being superior to the other. Just dont confuse a chain in place of the toplink as meaning modifying the cutter with chains to allow the a-frame to pivot. Two totally different things to attain the same end result