I have a managed package with a custom lightning page and several LWC's placed on it.
And I need to know Do we have the possibility to place this lightning page using "lightning out" into another system.
Maybe add all of these LWC components separately ?.
The problem is that I use a lot of modules in them : ( Platform Events, Message Channel, rest api calls to other systems and a lot of salesforce standard components and modules).
There is no documentation which modules will work and which won't in Lightning out: https://developer.salesforce.com/docs/component-library/documentation/en/lwc/lightning_out .
Does anyone know where I can check if these lwc components will work in another system using Lightning out ?
Unfortunately, you have to look up each individual element in the Component Library. Each component that supports Lightning Out will have "Targets" that include "Standalone Lightning App." I can tell you now that lightning-emp-api isn't a supported module, so you'll have to, at minimum, do some work to get Platform Events working in Lightning Out. You can still subscribe via a standard CometD library (e.g. via jQuery), but it's less straight-forward than it would be if you could use that component directly.