Hi
The uTasker project actively supported the AVR32 between about 2009 and 2012 and it was quite popular at the time. Since then I have never heard of anyone using it any more though and I haven't done any work with it myself for about 9 years. This means that I don't remember all of the details any more except that the AVR32 support is still 'included' in the project and it should be compatible with the present version.
These are the reference boards that it has been used on:
#define DEVICE_WITHOUT_CAN // AVR32 project doesn't support CAN
//#define AVR32_EVK1100 // evaluation board from ATMEL with Ethernet and LCD
//#define AVR32_EVK1101 // evaluation board from ATMEL with AT32UC3B
//#define AVR32_EVK1104
#define AVR32_EVK1105 // evaluation board from ATMEL with Ethernet and GLCD
//#define AVR32_AT32UC3C_EK // evaluation board from ATMEL with UC3C GLCD and CAN
//#define AVR32_UC3_C2_XPLAINED // evaluation board from ATMEL with UC3C Ethernet
The project supports USB device and Ethernet and most peripherals but never supported CAN.
UC3A, UC3B and UC3C devices are supported (AT32UC3A is used on the EVK1105, for example).
As of now these have become legacy parts and so no active work is performed, meaning that apart from the available code, support would be very limited as I don't intend to normally work with the chips again. Since the AVR32 peripherals are highly compatible with those on SAM7 parts the available drivers should however prove to be mature.
Any specific support would probably need to be organised/agreed on since this may result in the need to re-learn the devices and tools again, which can mean a lot of effort that is unlikely to be used elsewhere again.
Generally I recommend looking at using the i.MX RT 1062 (1051, 1052, 1061, 1064) in case of Kinetis replacement since they can usually be found in small/medium quantities and are a modern evolution which is very much in support/development focus.
Regards
Mark