Let's see here. Trades down from 50 hp tractor to 25 hp one, didn't get more ponies to avoid possible emission issues. Now finds new tractor can't mow heavy stuff like the old one, and is considering aftermarket/ homebrew ways to boost HP.
Most, including me, would figure you really need more tractor because your DIY power boost has fairly strong odds of bringing more headaches than the emission junk you sought to avoid.
For example, what does the turbo kit do to improve cooling, if anything? The boosted engine will make more heat as it adds power, something these little diesels don't tolerate well. If you don't also soup-up the cooling system, your turbo my live longer than the engine it's on. Just sayin'. And, you probably already know about stopped up radiators from mowing debris.
But it's your decision, not anyone else's. Whatever you do, I wish you good luck dealing with this.