Improve installer's internal checks or add "Continue anyway" button

Currently, it's impossible to install FirefoxPortable while an instance of FirefoxPortable is already running, due to this alert:
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Mozilla Firefox, Portable Edition | PortableApps.com Installer
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Please close all instances of Mozilla Firefox, Portable Edition and then click OK. The portable app can not be upgraded while it is running.
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ОК Cancel
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But what if user wants to install a 2nd copy of FirefoxPortable for test purposes into a completely different folder?
Currently, he is forced to close FirefoxPortable first. And this is both: very uncomfortable and actually unnecessary.

Could you, please, improve the internal checks inside the installer and show that alert only if the path specified in the installer matches the path of the running firefoxportable.exe process?