Is erasing the `misc` partition a solution to automatic/unnecessary boot into TWRP after having installed LineageOS 15?
Some comments for those who need (save your time to google):
What is the misc partition?

MISC - also FOTA on older devices
It's a tiny partition used by recovery to communicate with bootloader store away some information about what it's doing in case the device is restarted while the OTA package is being applied.
It is a boot mode selector used to pass data among various stages of the boot chain (boot into recovery mode, fastboot etc.). e.g. if it is empty (all zero), system boots normally. If it contains recovery mode selector, system boots into recovery mode.
It may also carry some necessarily required information in the form of switches to control hardware or settings related tasks such as CID (Carrier or Region ID) information and USB configurations etc.

Source: [INFO] ANDROID DEVICE PARTITIONS and FILESYSTEMS | XDA Developers Forums
Locating misc/fota folder
From TWRP terminal (or via adb shell):
ls -d $(find /dev/block -name by-name)/*

Windows equivalent of hexdump
Windows doesn't provide an equivalent command for hexdump. However, in PowerShell 5.0+, there is one with format-hex. Still, in my opinion hexdump is better.
Don't forget to backup
To create backup:
adb pull /dev/block/platform/soc/7824900.sdhci/by-name/fota fota.img

To restore backup:
adb push fota.img /dev/block/platform/soc/7824900.sdhci/by-name/fota

In my case it didn't work, so I restore it because only the OEM knows what it means