The recipe looks OK. Maybe add a little sauer malz.
During a mash rest at 140/145F a few things are occurring in the mash. Alpha is liquefying amylose at 1-4 links located throughout the chain (liquefaction), releasing sweet tasting, non-fermenting sugar and glucose (saccharification). Beta is active at the same time converting glucose released by Alpha into complex sugar (conversion) which yeast loves but not as much as it loves glucose. Now, here is the kicker, depending on the modification level of the base malt used to make the beer sometimes Beta is denatured and conversion will not occur or Beta can be very weak and conversion will not reach completion. Before that happens, a brewer adds an Alpha/Beta enzyme from a bottle. In Bavaria a brewer cannot add chemicals and chit is used or malt that contains the missing stuff is added.
Depending on the modification level of malt Alpha can be pretty beat up, as well. Usually, when it is advised not to add adjuncts it is due to Alpha having only enough power to cause saccharification in the malt containing the enzyme. A maltster is producing Marris Otter that is low protein about 8% which is great because there's a lot of sugar in the malt. The problem with the malt, it's very high modified which means that Alpha used up a bunch of power during germination and with the high sugar and starch content in the malt for Alpha to deal with, the enzyme won't have enough power to cause saccharification of added adjuncts.
Modification is listed on the spec sheet that comes with a sack of malt. The number is next to the name Kolbach and next to the acronym SNR. Percentage of protein, malt color, pH, extract efficiency, gravity per pound, beta glucan, FAN and a few more numbers are listed on the sheet. The sheet is used to determine the quality of malt. There's a bunch of numbers, chemical names and acronyms on the sheet. The numbers get there when malt is tested. Malt is tested because it's inconsistent.
When conversion takes place second fermentation is required due to maltose and maltotriose which are complex types of sugar. The beer is racked off the top of the goop after primary and transferred into a second fermentation vessel. During second fermentation, a second conversion occurs. After yeast wipes out all of the glucose during primary, maltose and maltotriose are left. During second fermentation yeast absorbs maltose through the cell wall and an enzyme within yeast converts maltose back into glucose which is expelled back through the cell wall and yeast uses it for fuel. Gravity reduces close to expected gravity. During the aging phase the same thing happens to maltotriose and natural carbonation occurs and gravity falls to expected final gravity. When maltose is present in beer and when the beer is primed with sugar or CO2 injected gushing and over carbonation happens.
Diacetyl is self inflicted, and caused by producing wort lacking in nutrients and by using poor yeast. When the rest is used the beer is krausened because yeast are beaten to death during the rest. The rest temporarily removes diacetyl, it returns. If you haven't produced beer with diacetyl, don't use the rest. It is better to correct the deficiencies than to stress out yeast.
During the decoction method when mash is boiling a bunch of decent stuff happens. There is a type of starch called amylo-pectin located at the tips of the kernel and it is the richest starch in the kernel. Amylo-pectin is very hard, heat resistant, complex starch. Within the starch is a type of sugar, A and B limit dextrin. Dextrin is tasteless, non-fermenting, sugar responsible for body and mouthfeel. The finest Ales and Pils are produced from dextrin rich wort.
The starch begins to "melt" slowly at 169F, it "melts" real fast when mash is boiling. During dextrinization, 149F and up to the time and temperature when Alpha denatures (162F), the enzyme liquefies amylo-pectin at the 1-6 links located throughout the chain and dextrin is released. At the same time Alpha is working on amylose.
Temperatures used with the infusion method are not high enough to cause the starch to enter into solution before Alpha denatures. The starch is left behind in the spent mash. It looks like small, white, particles.
Another important thing that happens when mash is boiling, precipitation of chemicals takes place in the decoction and mashtun, upstream of the boiler. When the decoction is added into the main mash it's used to reach activation temperature of an enzyme, the enzyme changes precipitated chemicals into nutrients. Wort from the decoction method is chemically balanced and rich in nutrients which reduces the risk of the final product developing off flavors associate with home brew.
When mash is boiled protein gum is boiled away and the viscosity of the mash reduces. Maillard Reaction takes place and Melanoidin forms but it takes an hour or so of boiling for the ducks to line up. When mash is boiling hot break can easily be skimmed off before the sludge hits the boiler. When the filter bed is settling a layer of tan and sometimes gray colored mud forms on top of the filter, it's protein that won't end up in the boiler. Hot break is way less in tri-decoction beer than in infusion method beer and due to the wort being clean, less hops are required.
Check out the recipes on Weyermann Malt website. Weyermann Pils light and dark floor malts are slightly under modified, that means that the malt is rich in enzyme content. The malt is low protein 8 to 10% which means there is a lot of starch and sugar in the malt. Take a look at Skagit Valley Malting and Pioneer malting. I have used Weyermann for years and about two years ago I purchased Pioneer Pils floor malt and mixed it with Weyermann Barke, German Hallertau and tossed in a mixture of 34/70 and 802 which works well for my taste buds. 802 works well with a dextrinous wort and 34/70 sharpens up malt character by drying the beer out a little bit. I use straight 802 with Pils, and believe it or not, in Oktoberfest because I like the way it finishes the beer. Instead of having a Lager character the beer finishes closer to a Pils, just darker and higher in gravity and Hallertau flavored instead of Saaz flavored.