So, as far as I know, you can't have more than four tools at a time.
Four tools should work with controllers, because, other than the sticks and triangle/square/circle/cross, there's also a pad on the left. So there are four keys for four tools (normal, tool1, tool2, tool3).
So... 4 tools should work with controllers?
However, I would like more use of "use Pilot tool" function. Since Hydrogen, Vent Chute, and Impact Bumpers have a deactivation time, most pilots don't do more than a split second on these tools. If you want them on longer, I guess you could just click again.
(leaving out Drogue Chute. That deactivation time is too damn low!)