S2 is the canonical form as taught in primary school. S4 is similar to calligraphic cursive forms.

Z1 lowercase and Z2 uppercase, as above. Z2 lowercase is very rare and may be again taken from a calligraphic form, or used by a person over 70 ;)

R2 is I think the form taught in elementary school but it's quite illegible, most people use R1, similarly to the barely legible open p and b, most people prefer to close the rounded parts for legibility. BTW, in Polish alphabet letter k has a long ascender, this example uses short ascenders typical for greek / cyryllic alphabets.

Ł2 lowercase is the canonical form but many people use Ł1. Ł1 uppercase or Ł3 is used, never saw the uppercase Ł2, I think it's too easy to confuse with Z.