The previous solution we used for monitoring and alerts was a home-made application which uses WMI queries to monitor systems on the network. Mobile PC Monitor is a much more robust solution, but I would be interested in having the option to add "agent-less" computers by adding them to an existing computer with PC Monitor installed, defining which objects to monitor on the remote system (a workstation or laptop), then having that remote system appear in Mobile PC Monitor and the Dashboard application as a normal PC.

Agent-less computers can be considered application instances. You can achieve that by writing a cloud-api based application.

Here is a really nice tutorial on how you can do that, it's really simple.

Also there are some features that can be used to monitor remote services too (Ping, Ports, Exchange, VMWare, SQL).

Also you can create a plugin that will be installed on a pc with Mobile PC Monitor installed that is used to get WMI information from remote computers and display / notify them on request. It's only limit is your imagination.