Mine sure does get laggy with all the mayhem. I do Mythic 3 dungeon crawling, and every now and then I have to sit in a corner of the dungeon to wait for the CPU to quiet (cool) down. But I'm betting that depends on what handheld you might be using. My current crawling device is an older LG single core, android 4.4.2, 1 gig of ram.
Its small size is easy to wrap my hands around.