TrustedZone, options to access internal flash asynchronously

I am currently working w/ a project that utilizes TrustedZone and PSA Protected Storage to read/write to internal flash that's accessible only in the secure partition (I'm using the flash to store data like states, configurations of peripherals, etc). However, I noticed the writes take a while (around 1-2ish seconds) and seem to be blocking calls. The project I'm working on needs to perform actions every 2-3ms, such as reading from peripherals, encrypting data, sending data w/ the radio, etc. so this behavior will not work for our requirements.

What options for flash read/write are available that are non-blocking, yet also in TrustedZone?

  1. Are there any Kconfig options, flags during function calls, etc. that can fix this issue and allow me to continue using PSA PS?
  2. Does PSA PS handle timeslots i.e., MPSL? Is there anything related to timeslots that I can try on my project to prioritize the 'every 2-3ms activity' over flash reads/writes?
  3. Would NVS be accessible in TrustedZone?
    1. We used NVS in a prototype, before we introduced TrustedZone. It would be ideal to reuse this.
  4. What other options are there that we can consider?
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