combat-utility-belt VS dnd5e-helpers

Alternatively, you could use the Starfinder system on square grid maps, and then a PDF viewer + hexagonal grid maps for Lancer. Rather than relying on two systems, have the more complicated system handled by Foundry, and run Lancer on paper, using form-fillable sheets. Since both systems are D20, you can still resolve everything in Foundry - you'll just need to either make some dice macros, OR (my suggestion) grab the Dice Tray module, which can make it so much easier to quickly resolve dice rolls. https://foundryvtt.com/packages/dice-calculator . You can also use Combat Utility Belt to manage your Lancer effects within Starfinder, granted that there will be a bit of setup. https://github.com/death-save/combat-utility-belt

combat-utility-belt - Every hero GM needs gadgets to keep their game safe from dastardly players up to no good! And where better to store those gadget than on your very own Combat Utility Belt! This handy-dandy combat aid comes packed with a bunch of gadgets to ensure you get a TPK every time...

Enhanced Conditions from Combat Utility Belt (there are others that can be used for it - like DFreds Convenient Effects - but CUB is simplest).

Combat Utility Belt: Mostly used just for hiding combat names, but lots of other functionality

I use this purely for the Enhanced Conditions/Condition Lab to put the CPR specific effects in (critical injuries etc..)

please be aware of this issue: https://github.com/death-save/combat-utility-belt/issues/429

Github link

You didn't state what system you are using, but if it's 5e, and if you don't mind a visual indicator that is not tied to CUB then checkout the module DnD5e Helpers. The section for Combat Action Management is what you'd want to look at. This shows a visual indicator for Action, Bonus Action and Reaction.

DnD5e Helpers: General helpers around 5e (eg. Regeneration prompts)

Use this module https://github.com/trioderegion/dnd5e-helpers

midiqol, there are also modules for cover, for eg dnd5e-helpers

This is one of the things the module Dnd5e Helpers helps automate. It is triggered when an actor with a feature called Undead Fortitude drops to 0 hp. It prompts you for the damage type, and gives you a button to roll their Con save, and healing them on a success. It's configurable too.

DnD5e-Helpers for managing the Regeneration of vampires as well as resetting legendary actions of legendary monsters.