Same, if you are concerned about the CEL get the active autowerke. its the best option on the market and comes with a no CEL guarantee.
Armytrix downpipes come with an O2 spacer thats how they try to trick the ECU, you can buy an O2 spacer from Ebay for $20 and put it on any of the MAD downpipe...
+1 i just downloaded it. it gave me a few options to select from for drives nearby with scenic views.
You can also check how long the drive approximately takes to plan accordingly.
+1 and most of them use 200 CEL cats so they will sound the same
i would go with MAD instead of VRSF
its less pricey, comes with a lifetime warranty and the wields are cleaner
https://x-ph.com/mad-b58-4-5-catted-downpipe-w-bracket-bmw-f-g-chassis-supra/
are you looking for power or sound?
if you want power, you need a tune. you can get bootmod3 to take care of the CEL or if you dont want to send your DME overseas, get a JB4 instead and pair with the active autowerke catted downpipe which does not trigger the check engine light
if you only want 30-40 whp more, i would not spend money on flashing. you can easily achieve that with the JB4 and you can customize the power curve to best suit your tracking goals.