It can feel awkward to impose a ~$250-400k mgmt. fee on a newly acquired company, especially if (i) the seller rolled substantial equity, (ii) the seller continues to run the company (full-time focus), or (iii) the company is facing turbulence.
One solution can be to share the management fee with the seller. If they rolled 30%, give them $90k of the $300k. Good optics, total alignment, pro-rata for ownership.
Be proactive: The seller won't know to ask, and often they won't even know about the management fee dynamics until after the txn has happened.