TSP ADVICE

Looking for feedback on my retirement/TSP plan.
- Current Roth TSP balance: $15,663
- Active Duty Army 1LT
- Entered service: 9 Jan 2018
- Commissioned: May 2023
- Current base pay: $6,617/month
- 100% C Fund

Contribution plan:
1LT:
- Jan 2026 - Jun 2026: 10%
- Jul 2026 - Jun 2027: 12%

CPT (Jun 2027 - ~Jun 2032): 18%

MAJ (~Jun 2032 - Jun 2040): Max TSP contributions annually

Career plan:
- CPT in 2027
- MAJ around 2032
- Retire as a MAJ on 1 Jun 2040 with about 22 years of service
- Legacy High-3 retirement

My plan is NOT to touch my Roth TSP when I retire at age 41. Instead, I plan to live off my military pension, any VA disability compensation I may qualify for, and possibly civilian employment if I choose to work.
The goal is to leave the Roth TSP invested and untouched until around 2059-2060 when I'm about 60 years old, allowing it to continue compounding for another 20 years after military retirement.
I'm currently projecting roughly $1M+ in my Roth TSP at military retirement and then letting it grow until age 60.
Does this seem like a reasonable plan, and what assumptions would you challenge?