1. All 8's and 9's are natural.
2. 3/2@r7c7 must be +13 (FNC).
=> Both 7/2s in W4 must be natural. (If they were +17 this forces the 3/2 to be {67} - FNC contradiction).
=> r456c9 = +21 including a 9.
3. If 3/2@r2c5 was natural this forces the 5/2 and 6/2 in n2 to be +15 and +16 respectively - which they can't be.
=> 3/2@r2c5 = +13.
=> 6/2@r2c4 cannot be +16 because that leaves no possibilities for 13/2@r2c5 (FNC).
=> 5/2@r4c2 = +15 otherwise the uncaged cells in W1 = +25.
4. At least one of the 3/2@r5c2 and 5/2@r6c2 must be plus 10. But they cannot both be because that would make r456c1 = +2.
5. Exactly one of the 5/2@r6c2 and the 7/2@r7c4 must be +10. If both were they would add to +32, if neither were the uncaged cells in W3 add to +25.)