Currently I am following <script src="//assets.adobedtm.com/a0387b609786fba259782cb644bc8cab7b9acc08/satelliteLib-3cf61e0fc94139116241dfa469da67d73e40.js"></script> to include the js from DTM. But somehow it is loading slow, should I keep the js for faster speed? Any help will be grateful. Thanks.
According to me, Your question is "can be keep DTM library file(appmeasurement.js) in our server. It's take some time to load is browser."
No, Keeping this file in server will stop DTM to work. The many things will not load like data element, rules and other tools which added in DTM(marketing cloud visitor id service, Google Analytics, Adobe Target etc.).