Which Express Entry changes actually affect your ranking?
Express Entry changes that matter to you are of two kinds: which categories are selected, and how large the invitation rounds are. IRCC refreshes its category-based selection lists periodically, and a round can be issued for one category rather than for the whole pool. Neither changes your CRS score — they change which pool your score is compared against.
A round size tells you how many invitations were issued; a cut-off tells you the lowest score that received one. Read together, they describe a single moment. A cut-off from one round is history, not a threshold you can plan against, because the next round may draw from a different category.
What you control is the evidence behind your score. A language test result, a completed educational credential assessment and work experience documented against the right NOC and TEER code all travel across categories. A profile built on documented facts can be re-pointed; one built on an assumption cannot.