You still have to trust Blockstream to keep all your personal information safe, and hope there won't be any leaks or attacks that will steal and sell your data.
Solution for this is to make your own Jade DIY wallet, and there are several options for everyone to choose.
CryptoGuide posted a wonderful video instructions how to do everything, with more details on his github page and this will have secure boot same as original Jade device:
https://www.youtube.com/watch?v=PeqP6oVnlIs
There is one more quick and dirty solution using Blockstream Jade DIY flasher utility BUT in this case there is no secure boot and flash encryption!
This works for TTGO T-Display, M5Stack Fire, M5Stack Black/Gray and M5StickC PLUS.
https://blockstream.github.io/jadediyflasher/
TTGO (Lilygo) T-Display ~$10 USD
https://github.com/3rdIteration/Jade/blob/master/diy/readme.md
M5 StickC-Plus ~$20 USD
https://github.com/3rdIteration/Jade/blob/master/diy/readme.md
M5 Stack Basic ~$40 USD
https://github.com/3rdIteration/Jade/blob/master/diy/readme.md
All this devices are running with Open Source code so I am adding it to my list of DIY open source hardware wallets:
https://bitcointalksearch.org/topic/list-open-source-hardware-wallets-5288971