How could the furlough of USCIS workers impact I-526 adjudication?

If the furlough happens that will be a highly adverse circumstance and most likely we will see further slowdowns.

The furlough will certainly slow down the adjudication process of petitions and applications. This is an issue that is applicable across the board at the USCIS and I-526 petitions will probably not be an exception.

The furlough announcement appears to be aimed at pushing Congress to fund USCIS'' $1.2 billion budget shortfall. If Congress does not bailout USCIS and the furloughs do happen, expect longer processing times.

If USCIS adjudicators are furloughed then adjudications would stop. Given what is happening with the economy, in my opinion, it is extremely unlikely this administration will furlough its staff. They will print more money.

Everything will slow dramatically if Congress does not refund them.

It depends on what departments get impacted most. Processing times for I-526 are already pathetic, so, more of that I guess.

Yes, it could. Most likely it would delay adjudications.