I have tested read, erase, and write on an Eon EN25QH16. The program asked me to send a report, so here it is.
I was using the most recent git version, commit 4524e5f73eff4f3244fc94ce87039af5480a16bc. I modified the makefile slightly to work with the current libftdi (v1.2), but these changes were only for the pkg-config name and fixing some include problems.
I used an FTDI FT2232H mini-module, configured to be self-powered. The target was mounted on a small breakout board with a 47nF bypass capacitor and connected to the mini-module with individual jumper wires about six inches long. The HOLD# pin was tied high at the device. The WP# was tied low/high at the device as described below.
The logs are (in order of operations): log_read: Reading before any erase or write operations were attempted. log_erase_wp: Erasing with WP# tied low (failed, and the chip contents were retained). At this point, I tied WP# high. log_erase: Erasing (succeeded). log_read_after_erase: Reading after erasing but before writing. The data was verified to be all FF's. log_write: Writing (succeeded with verification). log_read_after_write: Reading after the erase and write operations. The data read here was verified to be correct.