How do you transition from an armour to another?

I'm playing Shattered Pixel Dungeon. I used to play it with minimal luck, or skill, and I got back into it. First run in years and I'm deeper than ever before.

I'm running a Berserker with a +1 Flail and a +7 Scale Armour (+1 coming from the seal). I'm nearing the dwarf king (first time ever) and I got a +1 plate armour and 4 upgrade scrolls.

What makes more sense, hold onto the scale and pump that further or swap, dumping my 4 upgrades on it bringing it to a comparable power to my scale, banking on better future scaling?

I also got a +1 glaive. Slow as fuck but hits like a truck. The flail hits similarly (when it does) but it's faster...

Edit: I got a +9 sad ghost that could really use a better armour as well, he's currently on a +1 mail and it's, well, his glory days are behind him.