Captions: Style Presets
Importing an SRT allows for style presets, however, for captions that are created within Premiere, the same style presets can't be used.
Advice from Adobe was to export captions made in premiere as an SRT sidecar, then import them to use the preset. This seems like a long winded process, and would save so much time if it was fixed.
Additionally, copy and paste short cuts don't work on effects, in the effects control panel on caption files for some reason. Manually right clicking copy and paste do the job, but cmd+c cmd+v don't work. Just a bug I think.

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Adobe Staff - Nate commented
Give our new Beta a shot. This has all been redesigned to make this process much easier.
Details here: https://community.adobe.com/t5/premiere-pro-beta/discuss-new-captions-workflow-in-premiere-pro/td-p/11521841?page=1