The template adaptation system in cxserver mainly depends on availability of templatedata information in source and target languages to extract template parameter information. However, not all templates has templatedata defined. So cxserver fallback to regex based template param extraction from the template source code.
See https://regex101.com/r/Kxz2jd/1 for a working example of that regex. But, while fixing some edgecases regarding T208985: CX2: Support mapping templates based on their parameter names, a new regex was itroduced and used along with parameter hints that we can pass based on source parameters. I am finding this regex failing for most of the extractions, as illustrated in https://regex101.com/r/mPmftu/1
The original issue addressed in T208985: CX2: Support mapping templates based on their parameter names is not relevant now as those templates has templatedata. I propose we revert the regex to the old one {{3,}(.*?)[<|}] that is same in VisualEditor and based on https://he.wikipedia.org/wiki/%D7%9E%D7%93%D7%99%D7%94_%D7%95%D7%99%D7%A7%D7%99:Gadget-TemplateParamWizard.js
