max-length envelope on one generator, running slow to meet timing

QICK configuration:

	Board: ZCU216

	Software version: 0.2.267
	Firmware timestamp: Fri Jun 14 16:13:16 2024

	Global clocks (MHz): tProcessor 307.200, RF reference 245.760

	4 signal generator channels:
	0:	axis_signal_gen_v6 - envelope memory 524288 samples (106.667 us)
		fs=4915.200 MHz, fabric=307.200 MHz, 32-bit DDS, range=4915.200 MHz
		DAC tile 2, blk 0 is 0_230, on JHC3
	1:	axis_signal_gen_v6 - envelope memory 32768 samples (3.333 us)
		fs=9830.400 MHz, fabric=614.400 MHz, 32-bit DDS, range=9830.400 MHz
		DAC tile 3, blk 0 is 0_231, on JHC3
	2:	axis_signal_gen_v6 - envelope memory 32768 samples (3.333 us)
		fs=9830.400 MHz, fabric=614.400 MHz, 32-bit DDS, range=9830.400 MHz
		DAC tile 3, blk 2 is 2_231, on JHC3
	3:	axis_signal_gen_v6 - envelope memory 32768 samples (4.762 us)
		fs=6881.280 MHz, fabric=430.080 MHz, 32-bit DDS, range=6881.280 MHz
		DAC tile 1, blk 0 is 0_229, on JHC1

	2 readout channels:
	0:	axis_readout_v2 - configured by PYNQ
		fs=2457.600 MHz, decimated=307.200 MHz, 32-bit DDS, range=2457.600 MHz
		maxlen 16384 accumulated, 1024 decimated (3.333 us)
		triggered by output 0, pin 14, feedback to tProc input 0
		ADC tile 2, blk 0 is 0_226, on JHC7
	1:	axis_readout_v2 - configured by PYNQ
		fs=2457.600 MHz, decimated=307.200 MHz, 32-bit DDS, range=2457.600 MHz
		maxlen 16384 accumulated, 1024 decimated (3.333 us)
		triggered by output 0, pin 15, feedback to tProc input 1
		ADC tile 2, blk 2 is 2_226, on JHC7

	8 digital output pins:
	0:	PMOD0_0_LS
	1:	PMOD0_1_LS
	2:	PMOD0_2_LS
	3:	PMOD0_3_LS
	4:	PMOD0_4_LS
	5:	PMOD0_5_LS
	6:	PMOD0_6_LS
	7:	PMOD0_7_LS

	tProc axis_tproc64x32_x8 ("v1") rev 4: program memory 8192 words, data memory 4096 words
		external start pin: PMOD1_0_LS

	DDR4 memory buffer: 1073741824 samples (3.495 sec), 128 samples/transfer
		wired to readouts [0, 1]

	MR buffer: 8192 samples (3.333 us), wired to readouts [0, 1]