JSON signs with scoreboards don't properly evaluate @e selector

When I use @e for the player argument of a JSON sign scoreboard score, it doesn't seem to render the score for the entity, even if the selector only ever returns 1 entity, even if the entity has a score.

to reporduce:

1. create a new world
2. place a sign down
3. run the following commands:

/scoreboard objectives add hi dummy
/summon ArmorStand ~ ~ ~
/scoreboard players set @e[type=ArmorStand] hi 100
/scoreboard players set @p hi 50

4. change the block data of the sign to

{Text1:"[\"\",{\"text\":\"hi\"}]",Text2:"[\"\",{\"score\":{\"name\":\"@e[type=ArmorStand,c=1]\",\"objective\":\"hi\"}}]"}

5. the score should not render. Note that if you set the blockdata to

{Text1:"[\"\",{\"text\":\"hi\"}]",Text2:"[\"\",{\"score\":{\"name\":\"@a[c=1]\",\"objective\":\"hi\"}}]"}

it works.