Downtime Activities Feat Help

So I'm currently building a new campaign for my players and one of the things I want to add in and highlight is downtime. I want to create a feat that I can manually add to each player that has a drop down list of items to choose from like "Tend to Weapon" for a +1 bonus to damage with a specific weapon, "Improve Armor Fit" to reduce damage by your proficiency bonus. Small things that add a bit of flavor and keep people involved during downtime. The idea was that during rests or between sessions if the timing and space in-game allow for it, the players will choose one or two downtime activities, select the option from the drop down list, and the feat will automatically apply the bonus. Now some of these like improve armor fit will be hard to automate I'm sure but I'm curious how I can just get the feat to work with the drop down lists.

Currently running DND 5.5e. I have a few mods installed but can't remember each one off the top of my head. I have some coding experience as well so I'm not afraid to get my hands dirty with the coding.

Any help or advice would be appreciated!