Vorker builds the per head quote with allergens and dietary variants, confirms the final headcount, then invoices with the reference their finance team needs.

That is the normal case, so it is built for it. You say the headcount and the variants, and Vorker prices the base menu per person plus the vegan, gluten free or halal portions as their own lines, so the client can see exactly what they are paying for.
Vorker writes out the allergen detail per dish from the recipes and product information you give it, and keeps it with the booking so the same list goes to the client and the kitchen. You are still the one who checks and approves it before it is sent, exactly as you would with anything food safety related.
Vorker asks for the confirmed number a few days out and drafts the message for you. When it changes, tell it the new count and it reprices the quote, updates the portion list and adjusts the invoice, so you are not recalculating by hand at eleven at night.
Yes. Vorker remembers the billing quirks of each client: the purchase order reference, the cost centre, the right billing address and who the invoice goes to. It pulls the reference out of the email thread and puts it on the invoice before you approve it.
It drafts and sends the messages to your casual staff list asking who is free for a date, then puts the confirmed shifts in your calendar. Every message waits for your approval first, including a text to several people at once.
That is the size it is built for. Vorker is made for businesses of one to ten people, where the owner is also the cook, the salesperson and the one invoicing at midnight. There is nobody else to hand the office work to, which is the point.