Let me get started by saying that it doesn't differ too much for FID or ECID as such, it's more in what you tie into them. Instead of using different ID's, one could possibly create a different ruleset in Tags, or a custom method of running only limited set or rules, variables and events for those t...

The default should indeed be 2 years, I think there has been a small slipup defining 2 weeks for lifetime. As the document describes, there is no way to change this without e.g. a separate script that adjusts the lifetime (note that Target script will restore it to 2 years when run).  I'm curious: I...

Are you using the unified call or the new beta feature to separate Target call, named "Guided events"? Since Target with at.js runs independent of Analytics, it actually seems to have less delay than WebSDK and it's default model of a single call. This varies somewhat, but im general separate calls ...

Thank you for the added details. I will also clarify that what I meant was it takes about the same amount of effort to implement new custom metrics in Analytics as it does mboxes for Target, so I would always go with the former given the choice. With A4T there is a call made from Target to Analytics...

As @pradnya_balvir instructed on Analytics, I recommend this solution as well. Target reporting is very lacking and provides very limited options for reporting. If A4T is available, I recommend using it for conversions as well and reporting through Analytics. This doesn't require any additional effo...

This documentation is well hidden, likely due to some horrible decisions in naming things: Analytics product comparison and requirements | Adobe AnalyticsData Warehouse has no limit on breakdowns, while I believe Reporting API has the same limitations as Report Builder and is limited to two levels. ...

I could not duplicate this issue testing different number and type of reports. Possibly this issue relates to Adobe uses period as the thousand separator, while Excel seems to convert and interpret it as a decimal separator, at least in some cases. Making sure how Excel is setup could help with this...

This seems to be an issue with Apple's hybrid web component that is using ITP restrictions, which is likely blocking setting a cookie. Unfortunately I don't have an answer for you on what steps to take in allowing cookies to be set, but perhaps this will give you a lead. I also found this post talki...

This is a tough one, since as you said, it really depends on two main factors:Amount of page loads (traditional or virtual)Amount of custom non-pageview events (such as download or exit links, button clicks and so on)If we have the page view amount assumed, my personal method is something like this ...

The corresponding method would be to fetch projects, since there are no system defined reports anymore. You can fetch the available projects via the endpoint as shown here: Projects APIs (adobe.com)