Nice car ... The lag is part of owning a turbo car and even with a different turbo anything in the TD06-20G isn't going to start to come on boost until the mid 3000s to 4000 excepting if you do cams.
You could look at my dyno, then Scary's and then USA Dave's old foz to see the difference between the various CBRD/Blouch TD06-18/20G with various mods.
Mine is mild, Scary's is not so mild and Dave's foz went from mild to stupid