Run your whole financial life through a line of credit and your credit report notices. Whether your score cares depends on which kind of line you're using, so let's take them one at a time.
Personal lines of credit usually report as revolving accounts. Revolving utilization carries serious weight in most scoring models. Keep a personal line heavily drawn month after month and your score will likely sag. Dynamic Banking can be working perfectly while the score dips, because the score doesn't see strategy, it sees a heavily used revolving account. If you run the play on a personal line, expect some score noise and don't panic over it.
HELOCs are gentler. Scoring models often treat larger HELOCs more like mortgage debt, or leave them out of revolving utilization altogether. Treatment varies by model and by how your lender reports. Plenty of people run the full strategy on a HELOC and see barely a ripple. I'd love to hand you a cleaner rule than "it varies," but credit scoring is one place where hedging is just accuracy.
The score dip that matters is the one that lands right before an application. If a refinance or a car purchase is coming in the next six months, ease the utilization down ahead of it. Let the line of credit ride lower for a couple of statement cycles. You'll give up a few dollars of efficiency for a season and keep your borrowing power for the thing you actually need it for.
Long term, this strategy tends to help a credit report more than it hurts one. Debts get paid off, on-time history stacks up, and total debt trends down year after year. That trend matters more than the month-to-month noise. If you're still deciding which kind of line to open, HELOC or Personal Line of Credit: Picking the Hub covers the trade-offs.