Hey thanks for the question. Yes Pro Plus gives more included usage than Pro and this applies to all three models you are asking about.
Auto Composer 2.5 and Grok 4.5 are first party models and all three pull from one common pool called First Party Models which was previously called Auto + Composer. This was confirmed earlier in the thread about Grok 4.5 at Grok 4.5 pricing for subscription plans
The logic is simple. The higher the plan the more included usage in this pool. So on Pro Plus you will have a larger reserve for Grok 4.5 and Auto/Composer 2.5 before you hit the limit than on Pro. When included usage runs out additional usage goes on demand at the same rates without any drop in quality or speed.
Details on plans and limits are at Models & Pricing | Cursor Docs
Let me know if you have more questions.