I'm not sure, but what is your goal.
more sound, more power or both.
Personally I would go for an additional set of mufflers.
one for fun (open, absorption-type) and one to meet the regulations (preferred orginals)
I've build several mufflers by myself in the past. these were absorbsion type mufflers.
Stainless steel perforated innertube, aluminium endcaps and carbon outertube.
The lenght of the mufflers is app. 450 mm and Ø 90, weight 1,25 kg.
A few guys have been racing these "mufflers" in the Dutch national Supermono cup.
normally the mufflers produced a nice dark sound at 102 dB.
As the noise limit was reduced below 98 dB I stopped.
General, if you want power and sound, go for absorbtion type mufflers.