So, while I have an issue that relates to this, I'm unclear of the approved use of this property, if it has been wiped from the docs. Has it been or will it be deprecated? I'm running AppMeasurement 2.7.0 at this time.
The issue I am experiencing is that when the user clicks an exit link to leave our website, the exit link Adobe Analytics call (or something directly related) seems to be causing a second click event to happen on the element just before navigation, which triggers a duplicate click event being fired in our Optimizely metrics implementation. If I add that external domain to s.linkInternalFilters, the duplication error no longer occurs. But we can't add every external domain to s.linkInternalFilters, and we don't want to set s.trackExternalLinks to false unless it's truly necessary. We already have custom s.tl calls with extensive context data being sent out on every link, so the Adobe exit links calls are secondary, but it's sometimes been useful to have that exit link data when researching an issue. (Note that I have tried removing our own custom Adobe event calls so that only the default Adobe exit link request goes out, and still experience this duplicate click issue.)
While researching this issue, I found that setting s.useForcedLinkTracking to false may prevent my issue, but not only have I yet to understand what impact this might have on our analytics, again I'm unclear if this property should be used at all. I'll add though that this seems like a rather important and consequential function that Adobe Analytics is performing whenever links are clicked, so it's odd I never read about it before, anywhere. The Korean documentation says that by default "the AppMeasurement file executes tracking link calls and handles navigation events manually instead of using the default browser actions." That is actually what I've already been doing myself in our code on most site links; trapping the event and waiting a 350ms delay for a large amount of analytics pixels to fire, and then manually performing the navigation event. Finding out that Adobe was already doing this (or attempting to) was a surprise, I want to know where I can get more details on this.
@ncavanagh by reading your question it looks your exit link is causing trigger a duplicate click event in Optimizely metrics implementation. When you add those external links domain to your s.linkInternalFilters it treats external links as internal and does not fire external link default call.
If you using adobe launch or DTM can go to analytics tool and add those external link domains in never track field under the track outbound link section. It should solve this issue. How to do that ...see here https://helpx.adobe.com/analytics/kt/using/ez-exit-link-tracking-launch-feature-video-use.html
Note: This change will not impact over exit rate tracking in optimizely as for Optimizely to count a visitor as “bounced” or “exited,” it needs to wait for their session to end (in other words, wait until the visitor has not triggered any events for more than 30 minutes). As you are tracking click on exit link in custom adobe calls to should still be able to see those exit link clicks in adobe reports.
Fix optimizely implementation by uniquely countling link click on those exit links.
To your question - about using s.useForcedLinkTracking to false will/may only prevent app measurement to track exit link, which can be achieve by above fixes.