I know that this solution doesn’t really suit your needs but for others who might be seriously considering an iPad with this as part of their use case, the iPad does support the pen functionality in sidecar. It also works for any of the iPads that support both pencil and sidecar not just the pro model. I know a few designers for whom the iPad has been good enough at this that they ditched their graphics tablets.
If you are not using it with a Mac then there are apps that give you sidecar like functionality including pen support with other devices. I’ve never tried them but I’d expect it would be more something to try if you already have an iPad or are mainly getting one for other reasons and would see it more as a bonus rather than a must have primary use case.
To return to your original question, I have never used this device but I have seen people at work recommend them when this question has been asked on slack channels so from what I have heard it is quite good if you are looking for a portable extra display. The conversations didn’t really touch on experiences using it in more specialised uses (colour accuracy or things like that) so that might still be something to consider, but in general it seems to work well and be well made etc.