66 yr old(electronically illiterate) with first post here, and my first time attempting anything like this, so here goes. trying to upgrade 4412 xovers, so, first question is about identifying the caps on the board. there are 4 caps on the board(excluding 4 bypass caps), 3 are round, aluminum exterior, blue colored caps, one for LF cicuit, two for MR circuit. in the HF circuit, there is a totally different cap, which is oblong and has a yellow plastic exterior. is this a different type of cap that effects the HF circuit in a different way (warmer, or?)? if so, should the replacement cap be of a different type also, to continue this line of thinking? i was planning on using Dayton 1% metallized polypropylene, unless there are better caps (at a reasonable price)that will give more improvement.

should i eliminate the bypass caps?

is there a benefit in using 2 caps in parallel instead of just the one cap? (reducing ESR) if so, can you piggyback the caps, with the top caps leads twisted around the bottom caps leads and the bottom caps leads soldered to the board, or must the leads from both caps be inserted and soldered to the board?

hope i'm on the right track in improving how these 4412's sound. thanks much, in advance.

p.s. i know these are silly questions for for a lot of people here on heritage, but i have to start somewhere.