If it is Hobby Lobby, chances are you are working with brass and not real gold. The squares are bigger and fake gold does not adhere to fake gold. Hence you will have not a good burnishing effect that you get with real gold leaf.
The fake gold leaves are brittle, they break more easily than real gold and it is a good idea to use an oil based glue under them and seal them with a top varnish that will surely make them a tad duller but at least will prevent oxydation. But you surely know all this.

Now considering raised gilding, if you work with an oil based adhesive, anything goes. You can totally make raised surfaces with cheap gesso (acrylic), top them with oil based adhesive and then put your brass leaf onto it. That is what we do when we gild, for instance, an object not requiring real gold. The oil based glue dries very thoroughly and is not rubbery like most PVA based glues.

It is a heresy if you want to do illuminations with real gold though. In this case, you have cornelissen/roberson improved gold body, or miniatum by Kolner or a very good already made gesso made and sold by Jerry Tresser.

Making it yourself includes candy sugar, lead white, plaster, parchment glue (hide) etc… and is a longish and quite finicky process. Perfect if you need some decent quantities though.

It is another technique, because the plaster is fragile, the glue has some bad days but layers upon layers of real gold on top of it and some burnishing will give you the best and most stable gold you can find

I hope I helped a bit

Awesome ! I hope you’ll share the in progress picts!

Yeah, just have fun. those are alcohol based gesso so as long as you keep the lid on tight, they will last. The Roberson is a tad tricky to reactivate, it asks for a lot of heat so you will have to blow seveal times but you’ll see the surface shining when it is ready so, all good ! And it burnishes well.
Jerry tresser sells it on his website but beware of winter season, it doesn’t not like cold Wait for spring! http://www.jtresser.com/GILDING-SUPPLIES-2.html (scroll down) Possibly one of the best gesso

flat and quite smelly

Just my opinion, ok? By any mean, do your experiments as you feel like, it is part of the fun.

Imho, using a traditional Jerry Tresser gesso (and quite pricey at that) with very basic metal leaves, it seems like a mismatch to me. Traditional gesso is fantastic because it burnishes elegantly, layers after layers of gold. If you are to glue metal sheets to it, it is a tad overkill I am afraid.
Miniatum, which is plastic will be a better match for sure.
Or any oil based glue on top of any relief maker, even acrylic gesso.

Keep the good stuff for the good stuff

To be honest, I don’t think you can practice real loose gold 24kt leaf with mock up gold. They don’t behave in the same way. There is less statics in fake gold, it breaks, you can’t work the layers which are the essential parts of real gold gilding so yeah, it’s fun but not an accurate training in all honesty.

and the cold can be dangerous because gesso contains water, you don’t want it to freeze :/ No idea if it can come back without damage but well.. here it is a tad extreme, we are at -40F today X)

Unfortunately, gold prices went haywire a few years ago so you’ll find anything between $50 and 80, depending on carat. I buy at Currys but it is Canadian