Yes. Revenue running on molds or fixtures the customer owns can move to another supplier quickly, so buyers apply a lower multiple to it than to revenue on company-owned tooling.
More detail
This is the defining diligence question in plastics and a significant one in stamping, casting, and fixtured machining. The buyer will want a schedule listing every active tool, who holds title, where it physically sits, what the maintenance obligation is, and what the contract says about removal. Where tooling is customer-owned, other factors can offset the risk: long qualification histories, secondary operations the customer cannot easily replicate, or contractual notice periods. Where tooling is company-owned, it is worth making that explicit early, because it is a genuine competitive advantage that buyers pay for and that many sellers never think to mention.