Best way to cut them is from the rear surface using a plunging rail saw and guide rail, fine tooth blade (e.g 160/165mm needs something like 42 to 48t, but no higher). It doesn't really matter where the cut goes so long as it is not visible and it is adequately sealed (e.g silicone, D3 or D4 PVA, etc) to prevent moisture ingress. I do this on any unsealed surface such as rear edges of cabinets etc
At 80t the material load being carried in the gullets (which are smaller than those on a 48t blade) can become so great that the blade gets very hot and scorches the material. I tried a very high tooth count blade a number of years back and found that it cut more slowly (it tended to baulk if fed too fast, possibly because it was warping a little), that the cut wasn't as good as an OEM or better quality aftermarket blade (I had a Festool, the aftermarket blades were from Atkinson-Walker, Leitz and Freud) and that the blades tended to scorch more readily. They were so a different to the OEM blades ,(think about the effect of different kerf blades on your snti splinter strips). It is interesting that none of the top end marques (Festool, Bosch, Makita, Mafell, Metabo, Virutex, etc) offers blades with even 60t and most standard blades are 42 to 50t
At 80t the material load being carried in the gullets (which are smaller than those on a 48t blade) can become so great that the blade gets very hot and scorches the material, and that can also warp the blade, leading to poor edges. I tried a very high tooth count blade a number of years back and found that it cut more slowly (it tended to baulk if fed too fast, possibly because it was warping a little), that the cut wasn't as good as an OEM or better quality aftermarket blades (I had a Festool, the aftermarket blades were from Atkinson-Walker, Leitz and Freud) and that the blades tended to scorch the material more readily (no good for glued joints as glue won't adhere to scorched surfaces). The kerf was also different to the OEM blades ,(think about the effect of different kerf blades on your anti splinter strips). It is interesting that none of the top end marques (Festool, Bosch, Makita, Mafell, Metabo, Virutex, etc) offers blades with even 60t and most standard blades are 42 to 50t
The only test is to make actual cut in the actual material you will be cutting. This might be something like taking a 5mm trim off the end of a decor panel whete you know you will need to take, say, 20mm off for the final cut
I've generally used a router with a bottom bearing template trim bit. Makes for a neat cut out. If the cabinet ends are being civered by decor panels or hidden against a wall you just do the lot, otherwise the outer (visible) gable ends are left uncut and the rails carefully trimmed to size
Bottom bearing bit is good. It is a bit safer if you use a larger diameter bit (1/2in or 12mm) rather than a 1/4in diameter bit. The small diameter ones have a tendency to bend if pushed too hardGot router. A bit like this one would be okay
https://www.amazon.co.uk/Gasea-2-In...ywords=trim+bit+router&qid=1626644252&sr=8-22
YesDo you make cut a bit wider for adjustment up and down?