There are a number of form fields you can pre-populate for logged in members by using the option to allow the field to be populated dynamically on the Advanced tab of the field. For each field you want to pre-populate you enter a specific Parameter Name that starts with membersplash.
The available fields are:
Account ID: membersplash_acct_id
Legacy Account ID: membersplash_legacy_acct_id
Account Type: membersplash_accct_type -- Note: returns the name not the id of the account type, ex: returns "Bonded Member" not 17.
Street Address: membersplash_street_address
Zip Code: membersplash_zip
Billing Member Full Name: membersplash_billing_member_name
Billing Member First Name: membersplash_billing_member_first_name
Billing Member Last Name: membersplash_billing_member_last_name
Billing Member Home Phone: membersplash_billing_member_home_phone
Billing Member Cell Phone: membersplash_billing_member_cell_phone
Billing Member Email: membersplash_billing_member_email