You are describing a bypass valve, not a bypass filter. The bypass section of the filter is always working.

I am describing a bypass valve and some "bypass filters".
Some full flow oil filter designs have a bypass valve, and anti-flowback valve, integral to the filter and when the filter becomes clogged, it allows unfiltered oil to prevent oil starvation of the engine.
Some full flow oil filter designs have a bypass valve on the engine to accomplish the same concept. This design also has an anti-flowback valve located on the engine.Since I did not see either a bypass valve or anti-flowback valve on the filter cartridge, I suspected the latter.

Some two-stage or bypass filters have a "fine" full-flow and an "ultra-fine" bypass section. Some have a "fine" full-flow and "coarse" bypass so that there is at least some filtration of the oil rather than un-filtered. Given what I see in the filters, I suspected the latter in this case also.

Now I haven't studied the oil system on this car but maybe someone has. You tell me.............

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Sam

84 300SD 350K+ miles ( Blue Belle )

I cannot answer for Forced Induction or on other filter setups but I am the best qualified to answer for my setup.
If the extra filter I installed becomes plugged up the oil flow from the oil pump will continue to go through the full flow part of the lower portion of the stock filter and continue to go through the upper portion of the stock filter (the bypss portion of the filter) through the orfice in the hollow stem that is attached to the filter cap and down passed the stem check valve and into the crankcase just as it would if I had not installed my extra filter.

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84 300D, 82 Volvo 244Gl Diesel

The oil that goes through the bypass filter goes through the very small restriction orifice and straight back to the oil pan.