I had used Browserstack a long time ago. Can’t say I use them as much anymore. With the dominance of Chrome (also MS Edge), Firefox, and Safari rounding out the top 3 I’ve found most web standards are followed and the need for browser-specific code (ie: IE) is not needed as much as it used to be back in the day. That eliminated most of the reason to test cross-browser with any site regardless of where it was hosted. With email it’s a different story and you still need to test a ton.
Is there something that has come up in the past to take you down this road? And what do your current statistics tell you about who is visiting your site and what they are using?