I'm sure there is, and I respect that Howe cares about those things. With that said, I'd rather let Mitchell find the next Heung Min Son and Sadio Mane for us - both of whom he brought in for cheap. Hamstringing him with what looks like a Howe Veto just seems to defeat the purpose of bringing in Mitchell in the first place.
Of course, we don't know for sure to what extent Howe has say on transfers, but it seems a safe assumption that he has significant say, based on our lack of activity, and Mitchell's penchant for affordable youth talent, of which we've brought in almost zero since he's been here.