In order to get a handle on the performance implications of porting Parsoid to PHP, we need to evaluate the different components of Parsoid.
One of these components in the wt -> html direction are the various token transformers.
As part of T186912: Make token transform handlers unit testable, @Sbailey has implemented a Mock Token Transformer that lets us run token transformers individually by feeding it input tokens. This lets us both evaluate correctness as well performance of individual ported token transformers.
As part of this task, we should port the mock ttm code as well as one or two token transformers, and evaluate and document performance the PHP version compared to the node.js version.
QuoteTransformer is the obvious simplest one to port for starters.