If nether reactors are built 1 or 2 times onto bedrock, and the obsidian is mined out, the bedrock is replaced with obsidian which proves a way to enter the void.
MCPE-887
Entering the void via the reactor
Resolved
Invalid
0
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.