Existing subsidies don't exist any more really, Brexit ended any outside 'investment' in the Welsh agriculture sector.
Here's my comment from a previous post that might explain a little more for you.
I think they’re not looking into specifics with each farm in this case, which is a large part of the reason many of the farmers here are struggling to understand/accept the proposals. Time will tell if the Welsh Government intends to ignore that issue or if they want to try and work with the farmers in situations where having 10% of their land as forest is unreasonable/impossible, whatever the reason.
Also for what it's worth - a majority of farmers, in Wales specifically, did not back Brexit - I've seen a lot of "Well they voted for it so why are they mad", which is inaccurate.
Thank you.