Maybe it's best to send it back.. it doesn't sound like these people really know what they're working with, and you don't want any Gremlins on your canbus.
I see they're currently at an alpha-version of their software. As a software tester, this sounds like "it should not be outside the walls of the developer's office yet".
PF05 – PolarFIS MQB (alpha version)
https://www.autopolar.net/downloads/PF05_PolarFIS_Firmware_v0.1.3.zip
https://www.autopolar.net/downloads/PF05_PolarFIS_Firmware_v0.1.4.zip
My thoughts exactly....
However this is the same software released properly for the pervious MK Golf & Audi TT...
& apparently it works all ok on MK3 MQB Octavia....BUT like you I do not like being a beta tester...let alone an "alpha" tester...
Oh but we have item for sale.....yeah right....
Like I say I'll give the importers a chance to sort it out....if not then I'll get ( I will) my money back...& BTW the car currently has no fault codes & VCDS works all ok without the unit installed...
& as a last piece of info/question...... in the install manual for Octavia they suggest to remove the battery connections before you plug in their unit & then state you have to carry out reset procedures for various modules...Now this is fine & I know...
However I did not do this...I left drivers door open, key out of ignition, & wait for the interior lights/fuel pump to switch off...car now in sleep mode...NOW I plug in their module etc...no need to disconnect the battery as basically the electrical circuits are dead after the main "X" relay...
I have done this many times on various modules on this car & others as its a safe way to do module work & it does not generate fault codes & you have no need to carry out reset procedures unless whole new blank modules...e.g. I can unplug the CAN gateway & replug it in & it will not generate an "intermittent com fault with CAN" error which it does if you don't wait for the "sleep" mode...
So would disconnecting the battery do anything else?....I can't see that it can & that's from 23yrs working on VAG cars & using VCDS for many years...