Coincidentally, I am also using this method. While I know this isn't the safest solution for many people, it's the safest for me and I haven't had any problems in years. I also record information such as seed phrase, password, private key...in the notebook. But that is really dangerous because the paper is quite fragile and easily destroyed, I then bought 3 USBs for backup to ensure the safety of my information. Of course, teaching my loved ones how to use them is indispensable. But I want to add a little more about how to store our phrase. We should take the time to check USB periodically because we all know electronic devices have a lifespan and can fail at any time. Periodic inspection and timely replacement are very important.
By the way, I also just tested them and they are ok

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That's a pretty good way actually because apart from having written notes, we also have a back up in a flashdisk as a backup that you can have when some conditions such as the loss of notes or the dullness of the notes we make we still have that as a backup of our seed.
Regardless of whether this works for everyone or not, the most important thing in this case is that we should do a backup of the seed whether it is in written form or in the form stored in a flashdrive like you did because at the end of the day this is also important.
We want security in maintaining the assets that we have both in writing and storing in a flashdisk has weaknesses such as fading or illegibility of the writing that we make or a flashdisk that may become damaged but if we have a backup and do not make one then this is a good thing because if one is lost then we still have a backup that can be used as a precaution so that our seeds are not lost and our wallet can still be accessed.