Your comments

This thread might be too old now to get a response, but:

I also would rather not have the auto-addition of a period in Textastic, but I do want it to continue to work everywhere else, so I'd rather not turn it off at the system level. Could we have a toggle for this functionality in Textastic's settings, like we do for other iOS functions like auto-capitalization, auto-correction and smart punctuation? I'm actually surprised this wasn't already in that list.

Thanks for your consideration!