Warp Stabilizer is among the special-case analysis effects that will display the Full Res (ignoring Toggle Proxies). There is a note of this in one of the Help docs. Adobe Premiere Pro Help | Ingest and Proxy Workflow in Premiere Pro CC 2015.3 When you render Previews, Export Media or use certain Analysis effects (Warp Stabilizer, Rolling Shutter Repair, Morph Cut), Premiere Pro always uses and displays Full Res, regardless of the Toggle/Enable Proxies setting. The only exception is when you have Offline Full Res, but Proxy is Online, then Proxy is used. The current possible workarounds are to Offline your Full Res clips or disable Warp Stabilizer in the Effect Controls tab.
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