Today I decide to give a try and enchant a pair of metal boots (made from adamantine) lined with bodak skin. This lining was choosen because before I've seen a result of enchanting applied to full plate lined with the same material.
By the default set of armor been granted +3 to saves vs death spells, which was improved to +5 and 10/- negative energy resistance, which is huge, truly nice bonus in environment full of negative energy, undead, necromancy.
Frankly, I've been surprised when I looked at the result I got from boots' enchanting. By default boots had +2 saves vs death, which improved to +3 only and granted no resistance to negative energy.
I did not expect to achieve exatly the same properties set of armor had on boots, I understand that smaller parts of gear should have lesser properties, but the properties improve according to some sort of general progression where attributes either multiply by two, either two points add to the initial number. (+3 discipline becomes +6, +1 ac becomes +3, +2 becomes +4, plain items without bonuses become +2, etc.) This lining on boots doesn't maintain this progression.
My question are: what I've encountered is flaw in the design? Is it a bug?
If it's a bug, will it be fixed? And if it's a designed feature, is there any chance it'll be reworked? My idea was: the boots going to grant +4 saves vs death and 3 or 5 point of resistance to negative energy. Such properties can compete with troll lining. Enchanted bodak lining on boots, as it's implemented now, seems to be almost entirely useless, because of how easy to get your hands on death ward potions. Another reason is minor magnification (just +1 save) of the saving throw granted by lining.