Not really. The issue is that a single ECU implementation is both specific engine, engine subtype, transmission, transmission subtype specific. So you'd need to find an ECU for a 1GR-FE dual VVTi with an A750E or F transmission.
This being said, the data is in an EEPROM, and there are ways to both update the software, as well as the "maps" the software reads. I would expect than transmission shift schedules live in the maps as a combination of throttle position, speed, rpm, and some other factors.
So if you want to mess with that, you'd want a separate ECU, so you can throw the original one back in when things go weird. The caveat is that all things on the Toyota CAN bus systems are VIN-number and magic-number synchronized, and since it's a single ECU you'll need to set the VIN, determine the magic number, and then program all your keys into the new ECU, before things will work. This isn't something the ebay TechStream systems can do, you need the real software with the locksmith endorsement. The procedure is in the FSM, and it's not very pleasant, nor cheap.
A possibly better approach is to have a CAN bus client that reads relevant data (like a ScanGauge, but software-readable) and then tap into transmission control input between its bus client/ecu and the actual transmission, and override it from there. Not for the faint of heart, unless you can get both male and female plugs for the transmission interface and re-route select cables. Tapping into the 28ga or smaller cables is an exercise in frustration.
