Business Care rep located grandfathered Go5G Business Plus (TI) for $220 flat, but stonewalled on discounts. Can T-Force do better?

Looking for advice from anyone who has worked retention recently. What’s the best way to get a retention deal? Current Account: 4 paid voice lines on Business Advantage (TI) at $240/mo. Was moved from an older grandfathered plan. The Goal: Lower monthly overhead while keeping Taxes & Fees Included and gaining top-tier flagship trade-in eligibility ($800–$1,000) for upcoming device upgrades. What Happened: I called Business Loyalty/Cancellations tonight. The second rep I spoke to actually found the grandfathered 1–5 line Tax-Inclusive Go5G Business Plus code (Business Unlimited Ultimate TI) and confirmed he could move all 4 lines over for $220/month flat out-the-door with AutoPay. The Catch: At $220, it barely lowers my $240 bill. When I pushed for an Existing Customer retention (citing competing offers from AT&T and Verizon Business) He claimed $220 with full device trade-ins was already a great deal and offered to transfer me to generate port-out PINs. I declined, so my account remains untouched as of now. Questions: 1. What are the realistic odds T-Force on X (⁠@TMobileHelp⁠) can attach an existing-customer retention discount to this grandfathered code? If the discount is a hard "no," can T-Force reliably stack a recurring $20/mo bill credit to get me to $200 flat out-the-door? Or worst case should I just lock in the $220 flat Go5G Business Plus rate as-is to secure the full $800–$1,000 phone trade-in tiers without losing tax-inclusive billing? Not sure if I would do any better with ditching the biz lines and go over to a consumer plan?