William congratulations, I have had one for many years and I love it. So here goes. I used Kodak mounting tissue type II but unfortunatelly it is not very common so it is hard to find. I changed to the Seal archival mounting tissue and it works great. I liked the Kodak because it is a little bit thicker base and it would be great for Azo. The Seal will work great and you can remove the print if you mess up the board. Since I have not used the Light impressions tissue I am unable to tell you if it is good.
If you go to the photo techniques web site look under their "new products" file and you will see a tacking iron made by Vermark International. It seems these are the same people who make the Zone VI tacking iron, it is great, it slips just under the print and it is very simple to regulate the temperature. I would recommend this over the Seal tacking iron a 100 times. I have both and I love the little one. Since this is only a heating element it might work as you say and not give you too high a temperature. Which is what would worry me if the voltage was higher.
BTW you owe me a review of the Bergger contact paper.....