Help- Feels Gutless after silencer removed plus flatspot??

First time in a year of ownership that I am really not happy with my 200 n/a 2.0
Wonder if anyone can help or comment?

In a nutshell, car feels sluggish, hesitant and (feels) considerably slower after having the mid silencer removed from the standard system a few days ago.
Since then I have aa horrendous flatspot between 2400-2900rpm and then it feels pretty flat and 'restrictive', almost straining up to about 5000 .Then it's as eager as before. Also I get a pop and crackle when I change gear gentle and with little to medium throttle around 2-3k rpm, not sure if that has anything to do with flatspot?

Car was faultless before, serviced ever 8k miles with only the best (8000 miles ago) , sub 35000 miles.

Mods
KTR Panel filter
Uprated engine mounts
Mid silencer removed (excellent job by Longlife exhaust Brighton)

So I fitted panel filter a week ago, felt a tiiiny bit more urgent in mid range, no flatspot before or after at all, pulled very smoothly to the redline.

The car 'kangarooed' for the first time earlier, pulling onto a roundabout at around 2200 top. Wtf, I never had this before. (cable tie trick got rid of any issues months ago)

My mpg has has gone from a steady 32+ to around 28 since I reset it after exhaust mod.
Car now actually feels slower and is driving me crazy.

I have a 64mm tb to try on Monday and Cleopatra the Clio is booked in with AmD tuning in Essex on Thursday for a 'stage 1' remap.

I really hope they will bring her back to how it was and better but I gather they just do a generic map, not a custom one to fully address mods and importantly the drivability issue.

Silencer has a sleeve so it can be swapped back but I like the slight increase in noise and rasp.