Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Is it possible to double-stack half-pint jars? The steamer may not be tall enough or this affects the temperature.
Document: I've been disappointed with the way half-pint jars sit, or don't sit, on the rack. They tend to tilt, and I don't need the worry of having to stand them upright after processing in order for them to seal.So this evening, after processing 10 half-pint jars of pear jam, some of which tilted, I measured all the racks from every canning pot I have. And I just ordered an 11.6 inch replacement rack for the Presto pressure canner.
I cannot buy all new Ball quart jars at $1 each to replace all my old jars.This canner does not work well with pint or smaller jars. They tend to tip on the wire rack in the bottom. I have purchased the Presto Cooking/Canning Rack for Pressure Canner to place in the bottom so the jars do not tip. It has not yet arrived but was recommended by another reviewer. I was able to get 10 new Ball pint jars in at once.
I do not tend to use the heat gauge at the top of the lid because sometimes it will not have cooled down enough between sterilization and final processing. Instead, I start my timer when the steam is shooting out about 8-10 inches from the little hole on the side.I have never had a problem with any jars not sealing.
There are about a half dozen small gashes in it, like it was hit with a sharp object, & the gauge on top is scratched, making it hard to read. Since the box isn't damaged, I can only surmise that the damage came from the factory. Another fine example of cheap Chinese workmanship.
Secondly, it has circular ribbing on the bottom, which might be okay for normal stoves with circular round burners, but for glass top stoves, it keeps the water from boiling, because there isn't a solid contact between the heated surface and the pan. Originally, I had a Back to Basics steamer canner, and that one was made a lot more cheaply than this one. This model from Victorio at least feels like it is a thicker metal than the other one, and the handles are much sturdier.
Perfect - really like the temperature gauge and the fact that it does not need much water. However - it takes the same time as the water bath method - so don't count on a decrease in time.
I was really nervous about using a steamer for canning due to all the research I had done. This steamer put all my worries to rest. I LOVE the temp gauge and zone's. This way I know EXACTLY how long to steam. I feel very comfortable using it. I canned salsa and spaghetti sauce a few days ago. It worked fabulous. Looks very nice and cleans easy. BEST OF ALL IT WORKED ON MY GLASS TOP STOVE NO PROBLEM! !
After reading some reviewers stating that steam canning wasn't recommended by the USDA people and other people insisting they work well, I decided to do my own research. I found an article by Utah State University Extension regarding steam canning here: [...]This showed me that it has been tested, proven safe, but the USDA is not comfortable because they feel it has not been tested enough. How much testing do they want, really?The proof is in the pudding though.
While you can't do any canning that requires a pressure canner with a steam canner-this is a great alternative to the deep water bath canner. Mostly because it is less mess and eliminates the hassle of handling hot jars.
I am very pleased with the steam canner. I used it on my glass topped stove...with no problems.I used quart jars and canned tomatoes. The little guage on top the lid was very helpful. I will bemaking pickled beets and hopefully some apple pie filling too.
Answer: I think it would work!  There's enough room in there for a quart jar, so I'd take your 1/2 pts - stack them on top of each other and see how that compares to the height of a quart jar.  I'd suggest using some sort of "spacer" between the jars - just seems like a good idea.  And I would not worry about the temperature - everything in the canner will be the same temp - one it starts to steam and the gauge says you are ready!