If lose the warranty is not a problem for you then you should firstly change your oeminfo to C432, but don't forget backup your, late you can restore your oeminfo.I was buying the phone from the three network store. Money in hand no bills nothing. Yet the phone was locked on on three mobile but I unlocked it because I live in Romania.
But basically it's the same phone, so it should not be any problem, right? Or at least to find the global firmware, to be free of the network apps.
And also I spoke to the Huawei team and they told me there will be no pie update for the P20 lite
Check this thread => https://forum.xda-developers.com/huawei-p20-lite/how-to/guide-switching-oeminfo-versions-t3882537