How much does the weight of 2-of-3 multisignature inputs differ between P2SH and P2SH-P2WSH?
To calculate the block weight, you need to know the size in bytes of the non-witness data and the size in bytes of the witness data.

With a P2SH-P2WSH input, your scriptSig will always be 35 bytes. This makes the size in bytes of the inputs to be 36 + 35 + 4 = 75. The witnesses contain your signatures and scripts, so the witness for that input will be 1+m*(1 + sigSize) + SizeOfVarIntFor(RedeemScript) + SizeOfRedeemScript. For a 2-of-3 multsig input, you will thus have 1 + 2*(1 + 72) + 2 + 105 = 254 as the size in bytes of your witness.

The formula for calculating block weight is base size * 3 + total size. The base size is the size of all non-witness data, so your base size is 75 bytes. The total size is the size of all data, including witnesses, so your total size will be 75 + 254 = 329. Plugging this into the formula gets 75 * 3 + 329 = 554. Thus the weight of the P2SH-P2WSH 2-of-3 multisig is 554.

*Note that SizeOfVarIntFor(RedeemScript) is actually two bytes because you need to use OP_PUSHDATA1 since the length of the redeemscript is longer than 75 bytes.