communication with USB Serial device over the web

I have been searching for a way to communicate with our usb device (an NFC reader), the user should not have to install anything (some of our companies do not allow there employs to install anything on there computers besides the programs that are already installed).


option 1: chrome.serial (http://ift.tt/1l6Pd1G) chrome.serial is i think a good choice but it is being phased out within the next year or two, as described here: http://ift.tt/2bSo7PN


option 2: I have found was WebUSB API (http://ift.tt/1ZjgOzw)

But it requires an addition to the firmware, which we can do, and WebUSB API looks like the best option right now.


other options(not viable options):
- Silverlight (dead. supported till 2021)
- ActiveX (Only works on IE, security setting needs changing, certificates,etc, etc)
- Windows service/Form? (only works on windows, requires install)


So my question is, is there any other ways of communicating with our serial via the web? possibly similar to chrome.serial or WebUSB API but without the firmware change?