Mobster's logic is sound. To add the technical piece: OTR-AC (Ostarine acetate or the esterified version) is still Ostarine at its core — it's an androgen receptor agonist. Whether it's "non-suppressive" is debatable, and the lack of direct PCT studies means the question genuinely can't be answered definitively.
The broader principle: any AR agonist during PCT — even a mild one — risks blunting LH/FSH recovery by maintaining some level of androgenic tone at the hypothalamus/pituitary feedback loop. The HPTA needs a period of low androgen signaling to fully upregulate endogenous production. Introducing any AR agonist, even at low doses, potentially extends the recovery timeline.
MK-677 is a genuinely different case during PCT — it works through ghrelin receptors, doesn't touch the androgen receptor or HPG axis, and has solid rationale for PCT use (preserving muscle, improving sleep/GH during the recovery window). The case for OTR-AC or any SARM during PCT is much weaker mechanistically.
What actually preserves gains during PCT better than compounds: training volume maintained, calories at or slightly above maintenance, high protein, adequate sleep. These are underappreciated compared to the instinct to keep adding compounds.