DITRs can be super helpful if you sell out for them, but also aren't going to hurt you if you ignore them imo. Once I get to AAAA or worse on my draft board I start putting DITR candidates up there. I then deactivate any all poor candidates prior to the futures game.
In addition to Catchers/Relievers, I think First baseman & Starting Pitchers can also be great DITR candidates. First Basemen because they don't need AS, but get huge Range/Glove & Hitting increases. Starting Pitchers because they oftentimes have 4 or 5 pitches, which all get huge bumps. Also remember that switch hitters are great because that doesn't affect the overall requirement. Relievers also become super useful because they get huge STA bumps and can eat a ton of innings.
While the strategy above has probably led me to getting only 1 each season for awhile, It has led to really good players each season, guys who would be at least considered 1st round comp picks if not 1st rounders:
All the Way Mae
S11:
Player Profile: J.P. Nicasio - Hardball Dynasty Baseball | WhatIfSports - Solid switching hitting 1b with great glove and solid hitting ratings
S12:
Player Profile: Marv Demel - Hardball Dynasty Baseball | WhatIfSports - 71/50 DUR/STA combo is absurd, with 70+ in all pitching ratings.
S12:
Player Profile: Vicente Uribe - Hardball Dynasty Baseball | WhatIfSports - 73/49 DUR/STA with similar ratings as Demel.
S12:
Player Profile: Yasmani Martin - Hardball Dynasty Baseball | WhatIfSports - 49/49 DUR/STA w/elite pitches
S13: Left a 5 year pro activated and he never made it to the bigs
S14:
Player Profile: James Kuo - Hardball Dynasty Baseball | WhatIfSports Great Catcher Platoon VRHP. DITR helped his defensive ratings get even more absurd.
S15:
Player Profile: Johnny Latimore - Hardball Dynasty Baseball | WhatIfSports - Looks to be a solid SP prospect (projected to be 79 ovr after DITR).
S16:
Player Profile: Jim Stokes - Hardball Dynasty Baseball | WhatIfSports - Already a really solid ML RP with the potential to have 80+ CON/VL/VR/1P/2P
S17:
Player Profile: Luis Ozuna - Hardball Dynasty Baseball | WhatIfSports - Already a borderline ML 1b, hopefully VR gets to 70 with 85+ POW/Eye.
All very useful pieces, but no superstars obviously. Kuo/Stokes were one of the few guys I left activated w/3+ years of experience because they were AAAA guys already. Overall, I've found this strategy a very good tool since it really requires no resources besides maybe a decent scouting budget. I also love to load up on comp picks, so the DITR relievers are great because they have such a low ovr threshold to get a Comp A pick.