I think it's worth noting that squatting doesn't necessarily mean using a weight that bends the bar!!
Squatting with 20kg on your back doesn't need a cage, doesn't need a squatter, and isn't going to start adding mass you don't want (I know that regarding mass as a bad thing is kind of hard to comprehend
You can go high rep sets or do super dynamique jump sets.
You can alternate leg width during a set from very wide to very narrow.
You can incorporate calf raises.
You can even alternate good mornings with the squats during the same set or add a few lunges.
Get the 20kg on your back and do 25 reps. Don't worry about how long it takes, just keep the bar on you back. If you're good with 25 reps try 50! If 25 turns out to be too many do 10.
When you're done just shoulder press it off.
Repeat until you are sick.
If you have trouble feeling stable then buy a cheap bergen and put a few rocks, bottles (plastic) of water, bags of salt, or bags of sand in it and use that.
You can also use the bergen full of water bottles to do a hill climb. Heavy as you can manage (30 kg 40 kg 50kg !!!!), sky is the limit. Haul it up the hill and (important!!!) dump the water before descending so your knees don't take a battering.
Alternatively an old army kit back held in a bearhug while you squat is totally dumpable and will give an unbelievable full body workout.
It's not going to make you a strongman, or body builder: it's just a bit of variety.
No need to be too serious about it.
Just have a bit of fun.
It's all good.