Small Business Server 2011
WSUS Automated Maintenance WILL work on SBS 2011; you just have to install the system requirements for Server 2008 R2 (SBS 2011). Make sure your environment is up to date, especially Exchange 2010 should be on SP3 with the latest rollup. .NET 4 is backwards compatible and There are many users who have installed it on SBS 2011 and have had no issues.
However, do NOT install PowerShell v5 or higher as it WILL cause problems for SBS.
A Note to SBS Users
For those of you who have already Googled and have read that there are compatibility issues with PowerShell 3.0 or 4.0 and/or Windows Management Framework 3.0 or 4.0 and have seen all of the release notes and posts saying not to install these on SBS, please take notes of the dates of these pages and advice notes. Most of these are relying on and regurgitating old information. If a site has a recent post that says not to install it as there are compatibility issues, find their source of information and if you follow the source, you’ll notice that they are regurgitating a post from years ago. When you are reading things on the Internet, think critically, look at dates, and use your intelligence to figure out if it still makes sense. Don’t blindly rely on words on pages of the internet.
An example is .NET 4.7 which was released 2017.06.15 and which has a warning to not install .NET 4.7 on an Exchange server. This holds true until it can be properly tested, and if issues found, patches to .NET 4.7.x released for compatibility with Exchange. The biggest issue – all previous forums, blogs and writings on the Internet will not be updated to say that .NET 4.7 is now compatible to install on Exchange servers. This showcases my point that imagine in 2019 someone who is thinking about updating an Exchange server, Googling to find out if .NET 4.7 is compatible (when current version of .NET is probably around version 5.0 or 5.1) and finding all these warnings about not installing it on an Exchange server.
One note for any system, but something to mention specifically for this thought:
The best thing you can do is make sure your system is updated. Non-updated systems suffer problems and exploits that in the end, cause you more time in troubleshooting and fixing than to keep systems updated.