No EMI filter is needed, for the reasons you mention. A standard transformer is cheaper and performance is the same as toroidal.
You can save the cost of the inductor, you can salvage high-current toroid coils from discarded Desktop PC power supplies.
The switcher IC itself if probably 100% in spec, if you just swapped the inductor and catch diode and added a heatsink to the switcher IC, you would realize the full output current the IC can deliver, probably without problems from the original circuit trace widths.
If you chose to hack this board, you would be adding the more robust parts and this would require wiring to them, and you should use higher current wire, eliminating the trace size limitation problem.
In other words you could just salvage and reuse most of the parts, take all the parts, switcher IC and input/output caps and move them to a perfboard, but upgrade the diode and inductor.
If you are careful to use large enough wire in the common ground and high current connections in/out of the switcher to catch diode/filter caps and to the output, it would work ok at the chip's spec'd power output, even if you are cloning the new circuit on a simple perfboard. I've had done this successfully.