Yes there was no logging for EGL config back then because it just let it choose its own. The logging is in PPSSPP and was only added after.
I guess it's just from the depth=16 and alpha=8 that you lost the performance in that revision. Later when it was reverted, you may have lost performance for a different reason.
Example: 8/8/8/0/24 (fast) -> 8/8/8/8/16 (slow down!) -> 8/8/8/8/24 -> 8/8/8/0/24 (now)
Now that it has been reverted back to good config, speed should be back to normal. Maybe you have a slow down from something else as well?
I guess it's just from the depth=16 and alpha=8 that you lost the performance in that revision. Later when it was reverted, you may have lost performance for a different reason.
Example: 8/8/8/0/24 (fast) -> 8/8/8/8/16 (slow down!) -> 8/8/8/8/24 -> 8/8/8/0/24 (now)
Now that it has been reverted back to good config, speed should be back to normal. Maybe you have a slow down from something else as well?