I support this!
There could also be an array of variables
{seqn1} - starts from 1
{seqn01} - starts from 01
{seqn001} - starts from 001
{seqn0001} - starts from 0001
or even better...
maybe add parameters to {seqn} variable,
for example
{seqn} by default continues the counter
{seqn:1} - adopts current setting, but starts from 1
{seqn:1,0} - starts from 1, and adds one leading 0
{seqn:1,0,1} - could mean start sequence from 1, with one leading 0, and 1 increment, resulting in 01, 02, 03....
{seqn:50,000,5} - could mean start sequence from 50, with 3 leading 0, and 5 increment, , resulting in 0050, 0055, 0060....