Is there any thrust data available for the BF-34EI or BF-25EI spinning recommended props?
What would be required to fuel-inject these engines? Thanks.

There is no specific thrust information. Thrust will vary widely with different propellers, even the same-size propellers of different makes. Sometimes, you can have two props from the same maker that have the same diameter and pitch and have different thrust numbers! You have to try and see.

Fuel injection is a very complex subject. There has been no work on converting any of the Fuji-Imvac engines from straight carburetion to fuel injection. It would be difficult and quite expensive, and really not economically feasible.