Avoid parsing a variable to nil if not found

I have two components A and B. A and B both have variables that are specific to their respective components. A template string is entered in A which is then passed to B and is then published. I want to use liquid to parse only the variables that are available in A and ignore the {{ }} syntax in the string if the variable is not found, so then when the string is passed to B, it can replace those variables.

" Hello {{ a.var }}. This is {{ b.var }} " -> [ Component A ] -> " Hello world. This is {{ b.var }} " -> [ Component B ] -> " Hello world. This is liquid "

I basically want to parse a string twice, without converting missing values to "". Is this possible with liquid right now?

The issue names no files, tests, or entry points. Start by locating the template parsing and missing-variable behavior, then reproduce the two-pass example; done means the first pass preserves the unresolved {{ b.var }} while resolving A's value, and the second pass resolves B's value.