There is a little problem with item decay time. Item decayat do not reset when item is set to movable. (Fortunatelly, I can do it myself, because I can change .decayat member... but it would be probably better if core do that)

Problem occurs when for example: Item objtype has DecayOnMultis 1 in itemdesc.cfg, item is locked (unmovable) on house ground for some time, and then when someone will unlock it, item can immediatelly disappear, because decayat time is not refreshed. Decay sweep interval is like 10-20 mins (maybe the DefaultDecayTime ?), then it depends, sometimes it stays on the ground for a 5 mins more, and in another case it can stay on ground for a 1 sec.
I think it wont hurt if pol will update decayat member on Item.movable := 1;

Thanks.