Does anyone else break in a new blade in their mildest razor?

I have recently acquired a heavyweight all stainless steel Ikon S3S with the bulldog handle. It is a beautifully made razor and gives a super close shave. The only problem is that is seems to suffer very badly from the first shave on a new blade phenomenon, even with corking. I have so far tried Feather Pt, Derby Extra, Gillette super thin yellow, and Dorco Pt and all seem the same. My way round it has been to do the first shave with the new blade on my Gillette Super Adjustable, which is probably the mildest of the user razors I have. I set at 3 rather my usual 4 or 5. I do have a WW2 Feather which is even milder but I regard that as a collector not a user. After one day's break in with the Gillette, the blade is then perfect for use in the Ikon. For me Derby Extra seems to suit it best.

Wilson

My rule of thumb is not to pair mild blades with mild razors, since the shaves are generally unsatisfying. I don't mind using a sharp blade in an aggressive razor, but if it feels like "a bit too much" that way, then starting it out in a milder handle makes perfect sense.

I test new blades in my most reliable razor, the HD.
It's a good middle of the road shaver that, for me, allows the character of the blade to show.

Yup. I test new blades in one of my many Gillette Techs. I can get passable results from any blade in a Tech, but if it feels a bit "off" in the Tech, I don't dare try it in, say, one my my Old Types.

I use my Merkur 23C as a baseline razor.

It is a good idea to at least try one out in the razor that you use most, and are familiar with. Since you know what to expect from that razor, it would be easier to judge the blade. My 2 most used would be the DE89 and Gillette President, both are neither mild nor wild.