Cache directory not writable on Pantheon

I just moved a client site that uses this plugin onto Pantheon which write-protects the entire file system except for the uploads directory. As such, I’m seeing the following error:

Error : Please add write permissions on the following directory : /code/web/wp-content/plugins/locateandfilter/cache

Can you either move the cache directory into uploads, or create an option to specify where the cache directory should be?

In general, plugins should not expect to write data into their own directories in the file system.

Thanks.