BASH: IFfing throuth two (or more) folders to find files matching pattern

I have a bash-related question. To start the explaination. I had a folder structure looking like this:

config--
       |-config-chain.conf
       |-somefile1.txt
       |-somefile2.txt
       |-somefile3.txt
       |-somefile4.txt
       |-somefile5.txt
       |-somefile6.txt 

config-chain.conf contains text looking like this:

somefile1
somefile2
somefile3
somefile4
somefile5
somefile6

Before today, all those txt files were in one folder, so iterating through this was simple.

But the specification has changed and I have to do this the new way.

config--
       |-config-chain.conf
       |
       |--folder1--
                  |-somefile1.txt
                  |-somefile2.txt
                  |-somefile3.txt
       |--folder2--
                  |-somefile4.txt
                  |-somefile5.txt
                  |-somefile6.txt

Before that, I was iterating through this with a simple loop. It looked like this:

while read config-chain
do
    if [ -f $config-chain.txt ];
    then
        echo "Config file found"
    else
        echo "Config file not found"
    fi
done < config-chain.conf

But now the files are in two different folders. My actual approach is looking like this:

while read config-chain
do
    if [ -f folder1/$config-chain.txt ] || [ -f folder2/$config-chain.txt ];
    then
        echo "Config file found"
    else
        echo "Config file not found"
    fi
done < config-chain.conf

It is looking ugly for me, cause I'm looking for the existence of a file in both folders. I don't know how this will look in the future, maybe there will be 15 folders, so imagine this OR with 15 statements... Is there a way to do this cleaner? Maybe with find? Or a more clean way to do this with IF?