Working capital - simpler alternatives to TTM average NWC

I am looking for simpler language to use in the LOI to account for working capital without using the more commonly used TTM WC average. The goal is to simplify language to avoid f the hole that working capital negotiation can become.

My initial thought is that asking for ~6-8 weeks of expenses in cash at closing to cover expenses would be simpler to calculate and digest for the seller in the LOI. All I would have to do on my end is to ensure that this amount is enough to cover the cash outflows until cash comes in. Have you seen this before? Any other ideas on ways to simplify the