Agreed. 14hp on gasoline/petrol needs about 86cc/min (8.2 lb/hr), and that still leaves room at 85% duty cycle. Larger injectors are a conflict, and only used in some bikes using very high rpm, where there isn't enough time to inject before the cycle has passed. I don't think that's you.
The farther you drift from best flow rate, the more compromises you face. While you can force almost anything to run, the results are incrementally impacted. Use what you must, but otherwise use what you should.
Both MAP-referenced (MRFPR) and fixed-pressure regulators can work, however there are advantages to MR, such as better lower-load control and flatter tables as they try to sustain the rail/manifold pressure differential. Additionally, adjustable MRFPRs can let you dial-in the best compromise in pressure range and flow for your tune.
Fixed-pressure regulators were primarily adopted for multiple performance reasons — emissions performance and production cost performance — not for their power performance capabilities. While their appearance of simplicity may be attractive; the trade-offs are a host of issues that OEMs are willing to deal with for the benefits in regulatory compliance, and a bit less groaning by the accountants.
That said and again, use what you must, else use what works best for your application.
Search the forums for multiple options on low-power fuel pumps for EFI scooters, bikes, carts and ATVs. Some info for calculating required flow was posted here
. Another option is to run the smallest common pump you can find, and if oversized (it will be) control the power with either a Triumph-style idle-speed resistor (lowers pump power at low throttle), or a similar scheme run from the VVT output providing lower pump PWM duty cycle at lower loads. Have fun and enjoy that awesome R35!