Basic question about (M)STP with non-STP capable devices in path and link cost calculation

Hi, stupid question but if I have devices (wireless point-to-point microwave links in this instance I'm thinking of) that don't actively participate in STP but do forward BPDUs, this should be transparent to the switches processing STP BPDUs at different ends of the wireless link? So they simply see it as

switch1 <---BPDUs --> switch2

when it is in fact

switch 1 <-- BPDUs --> microwave link device 1 <-- BPDUs --> microwave link device 2 <-- BPDUs --> switch2

Even though there is a BPDU forwarding device that does not participate in STP between switch1 and switch2? I'm thinking about the way they calculate cost here, and which path would take precedence? My guess is that the switches would see it as 1 hop, even if it is 3 since they cannot know?