Is there any difference in a sequence coded as transition of coverpoint vs a sequence coded as a series of events in cover property

Coverage
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2

Not much difference other than $rose has the potential to become true on the first clock cycle, whereas the covergroup transition bin requires that sigA start at 0. Also, $rose is true for an X->1 transition.

If you coded the sequence as

sequence sigA_cov;
                @(posedge clk)
                !sigA ##1 sigA ##1 !sigA ##1 sigA
endsequence

Then they would be exactly the same.