Waveshare 2.7 inch and Pi 3B+ screen refresh rate can't be changed

**Describe the bug**
A clear and concise description of what the bug is.

E-Ink display is updated even when no major change takes place. In my case, the up-time count simply changes. Editing config.toml to change refresh to 0.0 doesn't work, changing the value even more also yields no results.

**To Reproduce**
Steps to reproduce the behavior:
1. Boot fresh installation of pwnagotchi 1.5.5 and observe the E-Ink display.

**Expected behavior**
A clear and concise description of what you expected to happen.

The display refreshes for only minor updates, about every 2-3 seconds

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (please complete the following information):**
- 1.5.5
- raspbian lite pre-made image
- Pi 3B+ and Waveshare 2.7 inch display

Reproduce the refresh behavior on a Pi 3B+ with the Waveshare 2.7 inch display using the pwnagotchi 1.5.5 image, then trace how the refresh value in config.toml is read. Done means the configured refresh value is honored and the display does not refresh for minor uptime-only changes.

Written by the indexing model from the issue text.