Digital control CC/CV boost DCDC chip/module?
Yes.  What you want is called a microcontroller.  Seriously.

There are whole families of micros that are targeted to switching power supply control.  Take a look at "motor control and power conversion" parts of the Microchip dsPIC series, for example.  These micros have a time base, fast A/D converters, and PWM output generators all built in.  You want to step up 48 V to 90 V at 700 mA.  That really isn't all that hard.

For example, you could run the A/D and PWM synchronized together at 100 kHz.  That means every 10 &micro;s you get a new A/D reading of the output voltage, then decide what length pulse to produce for the next PWM period.

A simple pulse on demand scheme might even be good enough.  You can set that up with no firmware overhead at all once it's up and running.  I've done exactly that several times in real commercial products to create various auxiliary supply voltages.  You can get micros that have internal analog comparators, and PWM generators with fault inputs.  The comparator output can be configured to disable the PWM pulse stream when a external voltage gets too high.  This automatically regulates the output voltage.

Since you want to drive LEDs, you can use this scheme with current feedback instead of voltage feedback.  When the voltage across a low side current sense resistor gets to the threshold level, the comparator trips and shuts down the PWM generator.  There are micros with internal voltage references which can be internally tied to one of the comparator inputs.  A few 100 mV for a current sense resistor isn't much compared to 90 V.

If the pulse on demand scheme is good enough, then even the tiny and cheap PIC 10F204 is all you need.  It has a analog comparator and 600 mV reference built in.  When the sense resistor output is below the 600 mV threshold, you do a pulse, then go back and look at the comparator output again.

This is exactly how my KnurdLight works.  It controls the current thru a LED string.  In this case, the LED string needs about 13 V at 20 mA.  However, the code in the PIC would be the same.