Hi RGeats
... in principle, having your mash at that slightly lower temperature during that time will slightly favour beta amylase (over alpha amylase), for slight longer, which may make the wort you make slightly more fermentable (see
there for more info (link)) ... but, in practice, mashing is a complex "balancing act" of temperatures and durations, and having your mash take a little while to "stabilise" at your chosen mash temp, will probably have less impact on the final wort than just how "stable"
your robobrew will maintain the mash during the rest of the mash duration and how accurately calibrated the temperature sensor of
your robobrew is at your chosen mash temperature
... and it looks like you've got a number of alternative methods to try, but since the robobrew will sort out your mash temp for you, whatever you decide to do about strike temp, I'd suggest you choose which approach to adopt more on what suits you, what fits best into your brewday, rather than fretting about every minute when the readout isn't your chosen mash temp
Cheers, PhilB