In order for there to be a dead zone at a position, you need a slot at which the players aren't being selected.
Those simply don't exist early for wide receivers.
The first seven players at wide receiver are all gone within the first 11 picks, and 14 are gone by the end of the second round. In PPR drafts, wide receivers absolutely fly off the board, eliminating early-round dead zones, but that doesn't mean we should simply ignore their positional ADP tiers.
We don't even get a chance to breathe here until the turn between the second and third rounds. If you were to pivot off of early-round wide receivers and snag a running back at some point, that might be the most fortuitous spot to do so.
Between the first 21 wide receivers off the board, there is a cushion of three picks between one receiver and the next only once, and that is at the aforementioned two-three turn. Once we get into the fourth round, though, this type of gap becomes a bit more common. We have six three-pick gaps between the 22nd-ranked wide receiver and the 30th-ranked player at the position.
When we combine this with what we saw at running back, a fairly clear strategy starts to form. If we want to avoid the dead spots at running back while getting as many wide receivers as possible before things start to spread out, we should be heavily inclined to select wide receivers with each of our first three picks. There are several dead zones for running backs in those first three rounds, and there is really only one, brief gap at wide receiver. The gap in cost between the 22nd-ranked wideout and the 30th-ranked guy is huge, allowing us to dabble at other positions in the downtime, especially at running back.
We do always want to be flexible about pre-draft strategies once the draft begins because we need the ability to adapt based on the flow of our specific leaguemates. However, based on looking at these ADPs, it seems clear that going wide receiver early followed by a pounding of the running back position is the way to go.