Update 2: So the WF-1000X does not appear to have any CXD chip in it, just the CSR 8675 from Qualcomm which I am guessing is being used for NC. Perhaps the WH-1000XM3 uses the CXD3775AGF chip which is larger. Seems like the WH-1000XM3 also have a dual mic system, or hybrid if you will ( 1) ( 2). It does seem that both the WF-1000X and WF-SP700N only have one NC mic, so perhaps they are using the CXD3774GF chip, which is only "Single noise canceling" and still a small chip, 3.4mmx3.6mm. The other two models only have singe mics for NC. I'm not sure what "Hybrid" Noise Cancelling (NC) means, but if it is the same as "Dual" NC, then Hybrid/Dual NC might point to the WF-1000XM3 which has two NC mics per headphone.
The CXD3781GF lists "Hybrid Noise Cancelling" as one of its features. There are two other wireless headphones that Sony lists under the "Truly Wireless" category (see Link 5) other than the WF-1000XM3: The WF-1000X and the WF-SP700N, both of which are lower priced models that don't mention the QN1e on their respective pages. The chip in question is quite small, 3.4mmx3.4mm, perfect for a small in ear headset like the WF-1000XM3. On Sony's webpage for the WF-1000XM3 headphones, one of the WF-1000XM3 "Key Features" is "Truly Wireless Technology" (see Link 4). One of the specifications of the CXD3781GF is "Hybrid Noise Canceling for Truly Wireless". I couldn't find any info for an exact-match CXD3781AGF search, but I did find a webpage (see Link 3) that lists a "Sony Audio CODEC" with a really-close part number of CXD3781GF.
Sony's site does state " Note: The image of code printed on top of the package has been manipulated", so perhaps 3775A_13Z is in reality the CXD3775AGF. This seems logical and most likely the case. If the CXD3775AGF has an etched ID number of 3775A_xxx, then the QN1e's etched number of D3781_xxx might correspond to a part number of CXD3781AGF. The linked images in this article for the WF-1000XM3 headphones show a QN1e IC with an etched ID number of D3781_835. There is a photo of that IC with an etched ID number of 3775A_13Z. Regarding the Sony QN1e Noise Cancelling Processor: The website for Sony semiconductors (see Link 1) has only one listing for an "Audio CODEC IC", the CXD3775AGF (see Link 2). Some more in-depth look at the parts, thanks to the kind user in the comments. If anyone has any actual information what the rest of the chips do, please leave a comment below. I am not sure if all of these are correct, I have copied some of the information from the translated article and others from googling them, like the memory chip, but the rest are unknown.