Yeah, it's possible. The square wave is generated from a PWM pulse train (PWM DAC) by running it through a filter to recover the average analogue level. So you can smooth the square wave by adding another filter, or by tweaking the one that is there. However, there are many possible causes of ticking, and very sharp edges on the square wave is only one of them. It's possible that the schmitt trigger switching in a typical op-amp LFO causes a voltage spike which could be heard as a tick. That's one problem that this LFO won't suffer from.
Mike might be able to advise us here, since he built a Tremolo with the original PIC VCLFO. I don't remember him saying anything about ticking.
In short, you're right to be cautious, but unless we've got an actual circuit and layout, it's pretty hard to work out ahead of time where the problems will come from. I haven't had any such problem, but I guess your mileage may vary. Please recognise that this is an entirely different design of LFO to most, and so is likely to throw up an entirely different set of 'unexpected features'!