I usually reduce development time by 10%, which has almost always been close enough to not need any adjustment. TMX wants around 5%.(posted 8622 days ago)I can't tell you anything about Ilfosol.
Generally, if you're developing film to the same CI in the same developer you'll get the same EI no matter how you agitate it; if you want to find out what's going on you'll need to do some carefully controlled test rather than using pictorial negs.
One thing to consider is that if a film/developer combination has some shouldering when using intermittent agitation, that shoulder may straighten up entirely when using continuous agitation. That _may_ be what you're seeing but with modern films the shoulder us usually _way_ above (higher density) than the range you'd actually be able to print.
Increasing dilution may help. Don't try to sneak up on it; use your original development time but double the dilution for a test. If that's ok then you're all set; if it's too flat then try 1.5X the original dilution.
Usually if you double dilution 1.5X the original time is a good starting point if the goal is to obtain about the same CI.
I often use D-76H 1:3 for a strong contraction using the 1:1 development time; HP5+ and TMX lose 2/3 stop and Delta 100 loses only 1/3 stop, but this is a _strong_ contraction, at least N-3.