Has that been an issue for you at all?
Yes and no, but mostly no.
My first type III was old school, and I didn’t care about the lack of handwarmers. Since then I’ve had som type III jackets and vests that include handwarmers and have had some use for them. The actual pockets themselves I never use, not even for warming hands. However, I do like the internal pockets that the handwarmers create for sticking my phone in. All that being said, I carry a bag with me at all times so it really isn’t a problem.
At the end if the day, many of the modified type III’s come up too long for me too, so the combination of a cleaner look, and a better fit far outweighs the lack of pockets.