problems with tolerence test

Hello,
I have been using my Ender 5 for about a month, and have learned a lot. I have upgraded the Ender 5 with the following:
all metal extruder, Capricorn bowden tube, SKR 1.3 with TMC2208 drivers. Skate bearing holder for the filament.

I have good control, now, of the Marlin firmware, and can modify it as I need.

I had been printing for TOO long before I actually learned how to calibrate the machine.
I just printed one of the tolerance tests, with two different filaments (both PETG) 0.4mm nozzle, and
BOTH failed, nothing turned as it should.

My extrusion cube test and CHEP cube are nearly perfect.

I printed a Benchy version last night and was pretty good, but the PETG is still giving me some stringing and
an occasional blob.

Am I supposed to switch to a 0.2mm nozzle before doing the tolerance and Benchy test???

pet-g does string a lot.
You basically need to mess about with extraction settings and most likely print slower.
Solid objects with little travel are always going to print easier as there are fewer retractions and no travel over open spaces.

But, yeah, basically it's down to getting the printing temperature and extraction settings to synchronise with the material being printed.

Pet-g is never going to print anything complicated at any kind of speed.