Spill Sensor/Ignition-Cycling Problem Part 3

I have a two part problem I'm trying to solve. 1. During colder weather, cold downdraft pushing down the flue leads to the spill sensor tripping. 2. With the basement window closed, the boiler short cycles. Both problems pretty much disappear when the window is open. I assume the spill is resolved because its heat operated, and when it's cold, the draft keeps the temperature low enough until the exhaust warms up the flue enough to work properly. I am guessing, with help from folks on this site and the boiler manufacturer, that the short-cycling is related to make up air. This theory was reinforced when the boiler was gasping, I turned off the two dryers, and it began to improve.

For the downdraft problem I have purchased an in-line draft inducer: https://www.supplyhouse.com/Tjernlund-D-3-D-3-In-Line-Draft-Inducer-1-20-HP-115V
This is a trial before moving to the bigger cost of insulating 35 feet of exterior flue that faces the street (where appearance matters more).

For the make up air… I notice two extremes in the recommended solutions for make up air. On one side, there is a formula for determining make up air and some fancy fan gadgets (e.g. fan in a can). On the other side, the boiler manufacturer and some pros say, "Well, just open up the window." I can't leave the window open all the time because it gets too cold and we lose a ton of heat. I'm having a hard time getting a pro to look at it, and I feel like I should try to work with the original installer as much as possible. He doesn't seem to be as knowledgeable as he led me to believe, but he's young and I think he wants to become that knowledgeable…

So what I'm wondering is something in between: For make up air, can I rig in one of these for now, to more efficiently draw in cold (make up) air? I'd mount the duct to the window, add a vent on the outside, and point the fan side at the boiler? https://www.walmart.com/ip/Industrial-Utility-Blower/5858259815?adsRedirect=true

I know it wouldn't be connected to the boiler on/off switch. And I know I should figure out the formula. But… I'm trying to be sure what's what before any major expenditures because I think make up air will be my responsibility, while most other cycling issues will turn out to be the technician's.

For added context, the open window is about six feet from the boiler, with a 16x28 opening. When open, the wind blows straight to the boiler. In addition to the boiler, there are six 40 gallon gas water heaters in the same area, and two gas dryers on the other side of a pseudo-wall. The basement door has been updated, some drywall has been added to fire retard the ceiling, but the four basement windows are 100 year old sieves.

Any thoughts would be appreciated.