Any solutions to create a Constant Sum / Slider-type question

Hello! Would love any advice on how to accomplish any of the following:

I’m designing a survey where respondents can allocate credits to a variety of choices, or keep those credits without allocating them.

The issue I am running into is that there are elements from both the Slider question type and the Constant Sum question type that I’d like to fuse together.

Specifically:

1) Snap to Gridlines Function: I need the ability to use 'Snap to grid lines' as respondents should only be able to select credit amounts that are by the 10's (e.g: 10, 20, 30, 40, etc.)

(This is something that the Constant Sum question doesn’t allow natively)

2) Constant Sum ~ Responsive Limits: Once respondents assign a portion of their total allotment to one or two items, I’d like to grey out the other bars and doesn’t allow them to assign more.
(This is something that the Slider question doesn’t allow natively)

3) Choices with dichotomous values (0 or 20pts): I have a few choices where respondents should only be able to allocate 0 or 20 credits to (for example, Choice D). I haven’t found a way to program those items to be fixed or static. (Currently all benefits can have any scale point value.)

Thanks!