I've been getting 100's of blank PCBs. several designs, from JLC, all with no issues. Most are 4 layer and go to a local assembler.
Last year started using their assembly services and after several hundred assemblies, 6+ different designs, all worked out really well. 100% yield after test. These are cards with > 700 parts per board: 0402, 0603, 0805, QFN20, QFP48, QFP100, QFP120, TSSOPs ...