Is there any concensus in lightweight steel performance around 90g?

B, I don't think there is a "concensus" as a lot will depend on what you're looking for. Around that weight class we have:

NS Pro 950GH (high 90's)

NS Pro 850GH (High 80's)

NS Pro V90 (90-100)

Shimada K's AC10 90 series (90-100)

Shimada K's AC10 80 series (80-90)

True Temper GS-75 (Mid 80's)

True Temper TX-90 (90)

Rifle Precision Micro Lite (90-80)

The will all have different feel and launch characteristics based on their bend profiles. Some are also constant weight while some are increasing weight (the Rifle's are decreasing weight)

B, I don't think there is a "concensus" as a lot will depend on what you're looking for. Around that weight class we have:

NS Pro 950GH (high 90's)

NS Pro 850GH (High 80's)

NS Pro V90 (90-100)

Shimada K's AC10 90 series (90-100)

Shimada K's AC10 80 series (80-90)

True Temper GS-75 (Mid 80's)

True Temper TX-90 (90)

Rifle Precision Micro Lite (90-80)

The will all have different feel and launch characteristics based on their bend profiles. Some are also constant weight while some are increasing weight (the Rifle's are decreasing weight)

Since you mention Shimada, T, I think the K3001 and 7001 are better than the AC10 (too bad Epon only lists ac10 as an option) and should probably include the K'5001 from SYB which is 89g. There is a nice extra kick with my 3001 thats not found in my nspro850.

You are able to get any Shimada shaft with all epon irons.

If you like lightweight lots of people usually do very good with the NS1050.