There is a saying that “the customer is always right”. I believe that there are exceptions to this theory. When a customer suggests that any flooring product be installed in a manner which would compromise the integrity of the installation, you are always best served by just saying no. Politely explain why doing so would not be in anyone’s best interest.
I realize that most sales personnel work on some sort of a commission basis, and the temptation can be strong to get the sale by whatever means may be necessary. Please realize that this attitude will not eventually lead to success, but rather ultimately to failure.
When problems inevitably occur, customers tend to have short memories. You will still receive call back requests, regardless of any concerns you may have raised verbally. Warranty claims will be denied. Friends and neighbors will see an unsightly installation and ask “who did that to you?” You can bet that only one side of the story will be told – and it won’t be yours.
Just say “life’s too short to purposely do things wrong” and move on. Your career will be better off for your having done so.