>>96309576
This increased size would also result in many of their low-level fighters being fairly deadly, too. For instance, daughters of rich families that want to go adventuring will often be given the means to grow by their rich families, for their safety and success.

Since I like the process of women growing bigger and suffering wardrobe malfunctions, that could be a part of gameplay where failing to use the growth method properly results in equipment being destroyed, or unusable while grown. You might also have clothes or armor designed to stretch and fold so that it can be worn at multiple sizes, though possibly less concealing in it's larger configuration, though that may cost extra.

The size faggotry will probably generally be used as lot in regards to their enemies and power levels. Size isn't everything, but is necessary against the foes this kingdom is fighting. Maybe giants. The result is multi-sized combat where normal troops of the kingdom face similarly sized troops, while the giantess troops engage larger targets. Sometimes the princess or queen enters the fight herself and becomes larger than most can, and engages the largest of the enemies. Since I like the equality aspect, despite the physical differences, her husband is probably commanding the army on her shoulder, using her magnified voice to issue orders he tells her.

Plot hooks would probably be similar to other areas. Maybe the PCs meet a noblewoman who wants to be an adventurer, but relies on the sizeshifting device too much, and this results in her eventually learning not to rely on it while the pcs babysit her until then. Or an attack by the kingdoms foes catches them unawares so you need to go titan hunting until the princess can get to your location. Or finding someone is smuggling growth potion to another kingdom and you can't let that shipment make it, possibly with a fight against a giantess without the best gear to take down a giant foe.