missing image file on disk with Minio will make Imageproxy peak

[Calx-Takeno]

We are using Imageproxy and Minio. They are good partner in most of time.
But we found mass of exceptions from Imageproxy console. So we investigate it.
When image file is missing on disk, Minio will return 'doesn't exist' xml.
So Imageproxy occur transforming error exception. And these exceptions are concurrency.
Traffic is more than 1k requests per second on our production server. Concurrent error exceptions make CPU/RAM/Disk-IO peak.
If error exceptions shot up suddenly. Imageproxy will crash.
We have set memery cache. It still consume hardware resources heavy.
I think error excptions are waiting for handling untill exceed of RAM range, this consume most of hardware resource.
Could you develop feature to ignore Minio 'doesn't exist' xml. Like cache initial params '-minio ignore-missing', Imageproxy will be better.
We have 2 nodes of Imageproxy. But they can not server our traffic well when mass missing image file request. Like missing file DDOS attacks Imageproxy.

Imageproxy version: 0.10.0
Minio version: 2019-08-07T01:59:21Z
Server Machine: windows 2016 x64, 8 cores/16GB RAM/1TB SSD