(EDITED)
Hey @lstrand,
I recommend against blocking User-Agents. You may end up blocking legitimate website visitors using the same User-Agent. Instead, block the offending IPs.
If you still need to block multiple User-Agents (i.e., cannot identify the specific, offending IPs), then use the Boolean operator “or” to separate each User-Agent.
So, in your case, you would use:
*Browser/9*.* or *Browser/8*.* or *Browser/7*.*
If the above doesn’t work, you will need to create a separate blocking rule for each User-Agent.
Additional, Useful Information: How to Block Bot Traffic from Menacing Sites
Last, you can always test your set-up by temporarily blocking a couple of User-Agents you’re using at this time, then visiting your own website(s). Make sure you always leave open one of your User-Agents so you can log back into your website (backend) to undo your test parameters.
Hope this helps.
Cheerio!