A milder deficit over eight weeks would probably spare more muscle. You are not starting from 40 percent so the muscle loss percentage will be higher as body fat gets lower. Adding a steroid cycle can help but moving to 200 mg test plus 3 IU of HGH means you are no longer on TRT and are enhanced which is fine if you are honest about it. There is no strong reason to rush straight to 10 percent. Take your time and do it properly.
I set a personal goal to hit 10 percent body fat even if I may not stay there long term. I have never been that lean and want to see how it looks. Right now I sit at 14 percent with a photo attached. I will run a strict four-week diet and share weekly progress pictures. My current stats are 88 kg at 181 cm so I need to drop about 4 kg of fat while holding a 1000 kcal daily deficit. I just finished a high-calorie phase. My current compounds are Retatrutide at 4 mg aiming for 5 mg per week with omeprazole for heartburn, TRT at 150 mg per week possibly raised to 200 mg to hold muscle, and HGH at 3 IU daily. I will keep posting updates and welcome any suggestions on how to make it work better.