Be aware that much of the iPad’s advanced functionality simply won’t work unless a Passcode is set (such as TouchID/FaceID and Keychain stored passwords) - and for this reason it may be beneficial to have this enabled. This does, of course, have some drawbacks.
Once set, should you choose to do so, you can turn-off the device Passcode from iPad settings:
Settings > TouchID | FaceID & Passcode > Turn Passcode Off
As documented by Apple in its Security Guide, for devices with TouchID or FaceID enabled, the device Passcode is will reportedly be required in the following circumstances…
• The device has just been turned on or restarted
• The user has logged out of their Mac account (or hasn’t yet logged in).
• The user hasn’t unlocked their device for more than 48 hours.
• The user hasn’t used their passcode or password to unlock their device for 156 hours (six and a half days), and the user hasn’t used a biometric to unlock their device in
4 hours.
• The device has received a remote lock command
• The user exited power off / Emergency SOS by pressing and holding either volume button and the Sleep/Wake button simultaneously for 2 seconds and then pressing Cancel.
• There were five unsuccessful biometric match attempts (though for usability, the device might offer entering a passcode or password instead of using biometrics after a smaller number of failures).
When Face ID with a mask is enabled on an iPhone, it’s available for the next 6.5 hours after one of the following user actions:
• Successful Face ID match attempt (with or without a mask)
• Device passcode validation
• Device unlock with Apple Watch
Any of these actions extends the period by an additional 6.5 hours when performed.
It may be worthwhile to directly contact Apple Support - and ask to speak with an Accessibility Specialist. Apple have a team dedicated to offering support for a wide range of accessibility issues.
You can contact Apple Support using the Get Support link at top-right of this page. Alternatively, you can initiate contact, or open a support case, using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:
https://apps.apple.com/gb/app/apple-support/id1130498044
I hope this information is helpful in obtaining the specialist help that may be helpful.