This article provides a general overview of questions and basic guidance around possible K2 patching and update strategies.
To be fully supported by K2 support and eligible for fixes for newly discovered product issues, you must run supported versions of K2 software (i.e. one whose standard support lifecycle have not ended) or have an extended support contract.
Refer to the K2 Product Support and Release Strategy page for additional details.
Before addressing these questions, it is necessary to distinguish between major and minor version updates as opposed to CU, FP and cold fixes. You can find some information about this here: K2 Product Support and Release Strategy.
Support assisted installation of codefixes is intended to make sure that they are applied correctly - when an installation is done wrong it may break things and/or generate new support tickets. You are always welcome to request assistance with codefix installation. You can reapply patches on your own if you are comfortable with that and if it is necessary, but at the very least the first installation should normally be done with K2 support participation.