If you are using dfx version 0.26.0 or higher, the dfx start command is already using pocket-ic by default instead of the local replica. See release notes and discussion here.
For most things, the behavior is the same and you might not notice a difference - the main differences we saw when we upgraded in the examples repo was around cycles accounting see this PR because pocket-ic simulates an entire subnet.
Some dfx commands that are replica specific will not work with pocket-ic, for eg dfx info replica-port will have to be replaced with dfx info webserver-port.
In short, I would expect some changes, but nothing huge - and I would recommend trying it out with 0.26.1 of dfx.
As far as CICD pipelines, I would recommend you take a look a the pocket-ic libraries. We’ve been using them quite extensively at DFINITY and folks seem to find them useful.