[tex4ht] ! TeX capacity exceeded, sorry [save size=100000]. with tex4ht only

[Karl Berry]

    save_size=1000000

I'm not sure if I want to increase the default save_size by 10x,
but if, say, 200000 (2x) or 3x is enough, I could change the default.
Can you give that a try?

After all, it happens for you on some large document, more than likely
it will happen to other people with their own large documents. And if
it's L3-related (not surprising), becomes even more likely, even
independent of tex4ht. --thanks, karl.