User blog comment:Willbachbakal/(Item Concept) Updating Mobility/@comment-24385282-20150316222418/@comment-1330314-20150321171845

You're right that Homeguard is the reason I'm adding a 12-second time, but the cost of switching from it to another enchantment isn't 500 gold, it's 75 gold: purchasing a trinket enchantment and switching to another (as is possible now with trinkets) would be the equivalent of selling it and purchasing another: you'd still end up with an enchantment in both cases, so that base cost goes out the window, so you're basically just paying for the swapping cost when going from Homeguard to another enchantment, which would be 250 minus 175, or 75 gold.

The reason why I think a 12-second timer is necessary here is because Homeguard already provides a bonus once you're at the fountain. In most cases, a 12-second downtime on enchantment swapping isn't a big problem, but it specifically targets Homeguard healing abuse, so I think having it wouldn't impact negatively on gameplay while still preventing abuse.