12 to 14 man + adding IDPs. Need advice

Wanting to add IDP this year to try and spice it up a bit but don’t want to scare away team owners from being overwhelmed. Adding a full 7 IDP is not an option so I’m thinking 3 would be a good median.

My concerns:
I don’t want the top IDPs to be valued as much as a top tier RB or WR. Simply because the position will be so new to us. It’d be nice to keep them comparable to a TE or WR2/3 in terms of points. Any advice on how to set up scoring to reach this goal?

Do I add flex IDP or just pick 3 specific positions? Pros/cons?

Yahoo league. 14man. 1/2 ppr. 1qb 2rb 2wr 1te 1flex(we/rb/te) 1k 1dst 5bench.