in case you are interested to test new fpga accelerators for a600/a500

[NorthWay]

IIRC it is not possible to boot any Amiga with a 68060 and any published Kickstart version only.

You need a bootrom at $F00000 or make your own modified Kickstart to not guru through the startup. MY Cyberstorm came with such a bootrom, and I expect all other solutions did too.
The 68060 simply came too late for C= to officially support it.

[NorthWay]

But maybe 68040 has same requirements, and bootrom is already present on 3640?

No, the 68040 is handled by Kickstart.

The missing bit is (I think - been a long time) to clear the "DFP—Disable Floating-Point Unit" bit in the PCR register and execute an FNOP before that.
IIRC it is the FPU tests that go wrong if this isn't done.
The 68040 does not have the PCR register.
If it simply works on a non-FPU 68060 I don't know.