Yes, or Vitainvest 100 Passive (0.90% total TER, btw newly available since this summer) for that matter. Lets say you are able to save 20k/year and need to amortisize 6.8k/year. Now you have to options:
A) Direct amortization. Save 0.60-0.90%/year on interest (or less after taxes) and invest 6.8k/year in Viac/Finpension and 6.4k/year IBKR.
B) Indirect amortitation. Invest 6.8k/year in the banks 3a investment solution and 13.2k/year in IBKR.
While the banks 3a will have a higher TER (0.90% compared to 0.45%), you’ll end up with more money when chosing B.