Could Webflow offer a cross browser testing service?
While that is a good idea, this is not something on our roadmap. There are free and some paid services that already offer browser testing. Each browser already offers internal testing. Chrome has a pretty decent one.
I would recommend BrowserStack.com for browser and device testing. When I do my testing I pay for the website testing, which is $30 a month. Not bad for when you are testing many sites across many different devices.
Please let me know if you have any other questions,
~ Happy Designing ~