The only way to reliably read a keypress is to use a trigger - either a Hot Key, Typed String or USB Device Key trigger.
It depends. If you want the number keys you type to be captured (ie, your macro sees them but they do not do anything else), then no. Because if you want them captured, then you need a macro with a hot key trigger of each number, and that macro cannot be active in general otherwise it would always be stealing those number keys.
If you don't mind the number keys performing their normal behaviour. Then you could have single macro with both the Hot Key trigger for Command-Control-Option-+, as well as a Typed String trigger with regex trigger [0-9] (without deleting characters!). And then the macro looks at the TriggerBase token and if it is the Hot Key, then you set a variable and wait for it to change, then continue on with the variable containing the number, and if it is a Typed String trigger, then you set the variable based on the TriggerValue token.
But if you want to capture the numbers and not have them perform their normal operation, then you want a second macro that is active only immediately after the first macro triggers.