My learning curve was coming from a little aluminium extrusion router to a Brother S700 with flood cooling. It's night and day what some coolant will do for the cut quality and time end mills last! YG1 fancy end mills on the router would struggle to last an hour or so of cutting, even with tiny step overs. Forget deep cuts, they would typically fail instantly.
Just learned this lesson again yesterday, see:
I was milling 1.5mm 6061 flat sheet. I milled some hundred or so parts, then turned off the coolant for a second to check the cut, and it made some rude noises. Then NEXT plate, it did that... Friction welded its way into the plate...
Cleaned it out, back in action and it did another 100+ plates without trouble. Lesson learned, beware turning off the coolant on more aggressive cuts
However! I also noticed that the very first hole it cuts on each part sounded terrible compared with the next 6 holes. On looking, the coolant doesn't switch on before the tool hits the part for the first hole (Speedios are fast...). Added a short pause before entering the cut and now all cuts sound the same. Massive difference from adding coolant!!
Anyway, that's my personal journey into learning the importance of coolant! (I'm no expert, new machinist, just learning on the job).
If I had to do your cut without coolant, then I would estimate the outside cuts would work ok, but slotting would have zero chance of success long term and I would expect chip welding every few parts... I would take a much smaller end mill and try a trochoidal path into it, with light cuts and lots of air blast. OR, slot down, but taking really shallow cuts with each pass?