You are essentially saying that improving the regex engine is not necessary

That's not what I read. More like changing the regex engine may not be necessary for the OP's real world problem (whatever that might be). If someone were to "improve" the regex engine to make this particular operation faster to run or easier to code, what would be the penalties for every other use of the engine? A workaround might well be the better option.

Generally, if an improvement can be made which neither breaks backwards compatibilty nor slows down any aspect of RE use nor introduces a forwards maintenance problem then I say go for it. Any other scenario should remain up for debate and decided on the relative merits/demerits.