My growth and dividend portfolios are already mostly focused on ETFs, such as LIT and QCLN. The problem is that LIT and QCLN have done so well that they took over my growth portfolio. Selling to rebalance could be one option, but feels like giving up on something that worked, and since they’re ETFs and not stocks, I don’t feel the need to really sell them since, as you pointed out, they should be relatively safe thanks to being ETFs.
You should have a target weighting in % for all your ETFs, and you should rebalance to that target either when it goes out of range (say 5% or 10% over), or every 6-months or a year. Your outperforming ETFs won’t outperform forever. If you think there’s a bullrun then let it ride, but know that eventually there will be a mean reversion.