See my other comment, on the backend they’re splitting donations above the personal per candidate per election limit across multiple candidates and elections, while allowing the contributors to specify a custom split that remains within applicable limits.

The duopoly knows how to siphon the cash as required.

> Harris Victory Fund accepts contributions of up to $929,600 from a person and $415,000 from a multicandidate committee (“PAC”). The first $6,600/$10,000 from a person/PAC will be allocated to Harris for President, with the first $3,300/$5,000 designated for the primary and the next $3,300/$5,000 for the general election. The next $41,300/$15,000 from a person/PAC will be allocated to the DNC. The next $510,000/$255,000 from a person/PAC will be split equally among the Democratic state parties from: AK, AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, and WY. Any additional funds will be allocated to the DNC, subject to applicable contribution limits.

In other words they’ve got an algorithm for that.