Gross Profit = sales revenue - cost of sales.From the Gross...

Gross Profit = sales revenue - cost of sales.
From the Gross Profit you then deduct all of the operating costs that are not directly related to the sales revenue (in this case, the cost of sales will be the costs paid to other parties in the payments process).

Where do you get your staff numbers from? I didn't see anything in the announcement of there being 20 or 30 staff being at Limepay.
What if Limepay has been on a cost shedding path to ensure its ongoing survival and therefore the staff are say 10 and they have gone completely remote workforce (i.e. not office rent). All this is pure guess work as there's no detail on this in any announcement.
By the way, worker's comp insurance is not a big cost at all, especially for office workers. It might be more expensive for trades/construction etc, but when the potential hazards for workers are things like paper cuts, the insurance premiums are small.

I also don't expect Limepay acquisition to be completed until late into this quarter, going by the timing of closing previous acquisitions.