I’ll try to keep this under 5,000 words 
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An “honest” voter approves of all and only the candidates they’d be fine with seeing on the SC. “None” and “all” are certainly possiblities! Either of those extremes will have the same effect on who’s elected (none!), just as if you hadn’t voted.
But they will keep your “active voter” status “yup, active”, and can have second-order effects in that total number of approvals reflect on how happy the community is with the candidates as a whole.
“Tactical” voters disguise their true opinions in order to try to influence the outcome. There’s not much room for that in this kind of election. In, e.g., pick-one plurality elections, it’s common as mud to vote for the lesser-of-two-evils major-party candidate rather than “waste” your vote on a 3rd-party predestined loser you really want. That’s tactical - not honest - voting. The system all but forces people into it.
But since we removed the limit on the number of approvals you can give, there’s never a good reason (neither real nor imagined) not to approve of everyone you really do approve of. You can try to game the system anyway, but you’re almost certain to fail .
That said, this form of multi-winner voting scheme is still vulnerable to “tyranny of the majority” and even “tryanny of a plurality” skewed outcomes, reflecting most-popular opinion in all those elected rather than reflecting the diversity of opinions in more-or-less matching proportions of winners different groups favor. More on that starting at the link below. Note I don’t claim that the alternatives mentioned are necessarily better or worse.