Thanks.

ipxe.iso is not reproducible it seems.

--- /gnu/store/gbik17qks3cijj2jazx9a6z1v7a5mari-ipxe-1.20.1
+++ /gnu/store/gbik17qks3cijj2jazx9a6z1v7a5mari-ipxe-1.20.1-check
├── share
│ ├── ipxe
│ │ ├── ipxe.iso
│ │ │┄ xxd not available in path. Falling back to Python hexlify.
│ │ │┄ 'isoinfo' not available in path. Falling back to binary comparison.
│ │ │ @@ -7,15 +7,15 @@
│ │ │  206d697373696e67206f7220636f72727570742e0d0a66606631d2660306f87b
│ │ │  661316fc7b6652665006536a016a1089e666f736e87bc0e40688e188c592f636
│ │ │  ee7b88c608e141b801028a16f27bcd138d64106661c3e81e004f706572617469
│ │ │  6e672073797374656d206c6f6164206572726f722e0d0a5eacb40e8a3e6204b3
│ │ │  07cd103c0a75f1cd18f4ebfd0000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │ -0000000000000000000000000000000088000000000000005e67d53200008000
│ │ │ +00000000000000000000000000000000880000000000000067458b6b00008000
│ │ │  0100173f20000000000000080000000000000000000000000000000000000000
│ │ │  00000000000000000000000000000000000000000000000000000000000055aa
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │ @@ -1023,15 +1023,15 @@
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0143443030310100202020202020202020202020202020202020202020202020
│ │ │  2020202020202020695058452020202020202020202020202020202020202020
│ │ │  2020202020202020000000000000000070010000000001700000000000000000
│ │ │  0000000000000000000000000000000000000000000000000100000101000001
│ │ │  000808000a0000000000000a1500000000000000000000160000000022001300
│ │ │ -000000000013000800000000080078040f142712000200000100000101002020
│ │ │ +000000000013000800000000080078040f142617000200000100000101002020
│ │ │  2020202020202020202020202020202020202020202020202020202020202020
│ │ │  2020202020202020202020202020202020202020202020202020202020202020
│ │ │  2020202020202020202020202020202020202020202020202020202020202020
│ │ │  2020202020202020202020202020202020202020202020202020202020204854
│ │ │  54503a2f2f495058452e4f52472f202020202020202020202020202020202020
│ │ │  2020202020202020202020202020202020202020202020202020202020202020
│ │ │  2020202020202020202020202020202020202020202020202020202020202020
│ │ │ @@ -1210,37 +1210,37 @@
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │  0000000000000000000000000000000000000000000000000000000000000000
│ │ │ -84001300000000000013000800000000080078040f1427120002000001000001
│ │ │ +84001300000000000013000800000000080078040f1426170002000001000001
│ │ │  010053500701beef0050582401c0410000000041c00100000000000001e70300
│ │ │ -00000003e7307500000000753054461a010e78040f1427120078040f14271200
│ │ │ -78040f1427120043451c0114000000000000140000000000000000ed00000000
│ │ │ -0000ed0060001300000000000013000800000000080078040f14271200020000
│ │ │ +00000003e7307500000000753054461a010e78040f1426170078040f14261700
│ │ │ +78040f1426170043451c0114000000000000140000000000000000ed00000000
│ │ │ +0000ed0060001300000000000013000800000000080078040f14261700020000
│ │ │  01000001010150582401c0410000000041c00100000000000001e70300000000
│ │ │ -03e7307500000000753054461a010e78040f1427120078040f1427120078040f
│ │ │ -1427120078002100000000000021000800000000080046010100000100000000
│ │ │ +03e7307500000000753054461a010e78040f1426170078040f1426170078040f
│ │ │ +1426170078002100000000000021000800000000080046010100000100000000
│ │ │  010000010a626f6f742e6361743b310050582401008100000000810001000000
│ │ │  00000001e7030000000003e7307500000000753054461a010e46010100000100
│ │ │  46010100000100460101000001004e4d0d0100626f6f742e6361740078003700
│ │ │ -000000000037c50a050000050ac578040f14271200000000010000010a697078
│ │ │ +000000000037c50a050000050ac578040f14261700000000010000010a697078
│ │ │  652e6b726e3b310050582401a4810000000081a40100000000000001e7030000
│ │ │ -000003e7307500000000753054461a010e78040f1427120078040f1427120078
│ │ │ -040f142712004e4d0d0100697078652e6b726e008000220000000000002200a8
│ │ │ -00000000a80078040f14271200000000010000010e69736f6c696e75782e6269
│ │ │ +000003e7307500000000753054461a010e78040f1426170078040f1426170078
│ │ │ +040f142617004e4d0d0100697078652e6b726e008000220000000000002200a8
│ │ │ +00000000a80078040f14261700000000010000010e69736f6c696e75782e6269
│ │ │  6e3b31005058240124810000000081240100000000000001e7030000000003e7
│ │ │ -307500000000753054461a010e78040f1427120078040f1427120078040f1427
│ │ │ -12004e4d11010069736f6c696e75782e62696e008000d9000000000000d99200
│ │ │ -00000000009278040f14271200000000010000010e69736f6c696e75782e6366
│ │ │ +307500000000753054461a010e78040f1426170078040f1426170078040f1426
│ │ │ +17004e4d11010069736f6c696e75782e62696e008000d9000000000000d99200
│ │ │ +00000000009278040f14261700000000010000010e69736f6c696e75782e6366
│ │ │  673b310050582401a4810000000081a40100000000000001e7030000000003e7
│ │ │ -307500000000753054461a010e78040f1427120078040f1427120078040f1427
[...]

Otherwise really cool!