Transaction fees can skyrocket anytime due to those garbage that are using bitcoin network but this not often and that is why whoever is DCAing should consider high transaction fees in future so that you don't end up using your profits in the long run to pay for high transaction fee.
This is why it is good that if you are DCAing when the transaction fee is very low just the way it is currently, you can consolidate y our small inputs into a big output for the future. You should make sure that the smallest input should be from $500 and above in one transaction to enable spend little fee in future.
That's decent advice, especially for those holding in non-custodial wallets (as they are supposed to) and DCAing often, i.e. every week. Assuming such investors would want to sell eventually, ideally at the peak of the bull run, that's exactly when the probability of a clogged blockchain and transaction bottleneck (aka high fees) is high. It's hard to predict how bad it can get, so consolidating from time to time during quiet time sounds like a good idea and doesn't require much effort.