as soon as i go past a smidge of finger tight they just stay locked on
a few possibilities
1. the brake posts on your bike frame may have rough surfaces. if you take the brake arms off, you can use a high grit (i.e. 800+) sandpaper to 'polish' the posts a bit. this is also a good time to put a small dab of grease into the brake post threads after sanding.
2. inside each brake arm, the area that contacts the top of the brake posts, would "grab" the brake post if you're missing teflon washers. i dont have those brakes so i don't know what they use in there, but you can try dropping one (or two) of those tiny, super thin white plastic washers into each arm before you put the brakearm onto the brakeposts, so that the washers act as a minimal friction surface.
3. by the same effect, try adding a teflon washer under the bolthead
4. one of the common workarounds is just to add a rubberband onto the spring to increase tension, so that the spring + rubberband combo has enough tension to overcome the friction and pull the brakepads away from the rim. This may not work for you, however, seeing that the arms already get locked when the bolts are finger tight.
The suggestions above are not mutually exclusive, and you can try them in combination. i hope this solves it.