Honestly, restricting Meta too much with a cost per result goal rarely works well, especially on smaller or mid budgets. I only use that bidding when I've got stable historical data, a consistent flow of spend, and a realistic CPA I've already validated through previous campaigns. Otherwise the algorithm gets too constrained, struggles to exit learning phase, and you end up with a CPA that's double what you'd get from highest volume.
From a data standpoint, scaling isn't just a bidding switch. The real leverage is in your message, ad creatives, and targeting. Get hyper-specific with your audience: who exactly are they, what's the specific problem they're facing, and does your offer solve something painful enough to trigger action? If that's dialled in, highest volume bidding usually lets Meta find the converters itself.
Also, a lot of the advice about throwing 4-5 videos and 10 ad variations together? If the core positioning is fuzzy, that just burns budget faster. Better to nail the offer and make the value crystal clear inside the ad itself before adding more creative volume.