Mash rakes are typically employed on much larger systems because they are usually heat maintained via a steam jacket and it's imperative to move the freshly heated mash away from the jacket to allow cooler mash to take its place.
Without that large surface area heat source, aggressively moving the mash around will probably cause faster heat loss despite the whole mash being more homogeneous in temperature.
What's your heat source? RIMS can mean a few things like direct fire, electric heated tube....etc.
Have you insulated your mash tun? I'm assuming it's a bare 30g kettle rather than their infusion tun.
Bobby - I found that even on a small 30-40 gallon capacity mash tun that is very well insulated, there still is a significant difference in heat distribution. I pre-heat my MT that is double wall, very well factory insulated SsBrewtech tank, with about 10 degree water from the HLT, above my mash-in rest step. I then mash in, and then use the 220VAC RIMS (also Ss Brewtech), to recirculate to dial-in very precisely, the temperature of that rest. Even with a pre-warm up of the MT, there is about a 4-5 degree drop in temperature, when I start circulating, compared to what my thermowell is telling me. Transfer hoses are short, and I do realize there will be a heat loss exterior of the MT while the wort is circulating. Honestly, I was surprised at how much difference there is in a relatively small tank, until I got the RIMS setup a year ago. I was also super stoked at the improved quality of the beer now, just by precisely controlling the Mash temperature. My last American Lager with 30% rice, Rest at 146F, 90 minutes, really needed to be raked about 6 times during the rest.
This is what I am trying to automate. There is a HUGE difference, between guessing it is 146 (maybe 142 or 152??) when you want a super clean finished beer with no residual unfermented sugars. I would rather be weighing out my Hops, possibly catching a quick bite of lunch while watching the temperature, and switching on/off the RIMS as needed, instead of raking the grain.
As
@day_trippr said, "would be money, time and effort better spent elsewhere.", I agree! But I honestly have everything a big brewery has (almost), on a smaller scale, and at this point, my "wish list", is practically nothing needed - Except a RAKE!
The other HUGE difference in quality of beer, is the precise control of your Fermentation. Once I put online the Raspberry Pi, BrewPi, 7 years ago, the quality took a big gain. I was using a Johnson control before that, and it was "ok" within 2 degrees, but now with the brewpi, it is fractions of a degree and setting the Profile to ramp up or down, over several days, really made my "guessing" go smoother, not having to keep reprogramming the 2 degree on/off cycle of the old controller.