I would say that similar work is already under way, we scientists can already "create" cell lines and mutant strains(single cells, drosophilia, zebra fish, worms like caerabinopsis elegans, dog, cats,...) by genetic recombination. Actually in your case, the "egg" implantation may work well because I guess that modifying just a few gene wont modify the compatibility of mother/mutant offspring that much. Note that only a few genes can alter strongly the phenotype (the appearance of your species or its ability and characteristics, like life span). Humans have after all only 2% genetic differences with Chimpanzee.

So to as an biologist, I would say

1 - genetic recombination and egg implantation work. Taking into account immunological properties makes it more believable maybe.

2 - Alternative is a pod with embryonic fluid. Some tissues sheets can easily be grown in lab culture, so in few years we actually expect to grow organs. Artificial embryonic sacks are thus plausible in a close future, and could be used in various situation.

3 - if you want a single organism that create offsrping and evolve without any interaction with a male, it is absolutely possible. There exist several mode of "duplication" of the organisms. By Fission, you can separate the body into 2 (usually for microbes), Division and regenaration (in that case you have the same genome accros multiple generations), but if you want to create evolution and diversification within your species, you can use auto-sexualization, etc. Some intringing lizards and frogs species do it :) The change of sex mostly depend on environmental conditions, such as temperature. I suggest you to google evolutionary website to check the strange sexual reproduction modes.

Scientists can already "create" cell lines and mutant strains(single cells, drosophilia, zebra fish, worms like caerabinopsis elegans, dog, cats,...) by genetic recombination. Actually in your case, the "egg" implantation may work well because I guess that modifying just a few gene wont modify the compatibility of mother/mutant offspring that much. Note that only a few genes can alter strongly the phenotype (the appearance of your species or its ability and characteristics, like life span). In fact it was suggested to create a Mammoth embryo and implant it into a elephant. Humans have after all only 2% genetic differences with Chimpanzee.

So to as an biologist, I would say

1 - genetic recombination and egg implantation should work if species are close enough (size matters usually). Taking into account immunological properties as suggested above may make it more believable.

2 - Alternative is to grow your species in a pod with embryonic fluid. Some tissues sheets can easily be grown in lab culture, and recently even some organs ! Artificial embryonic sacks are thus plausible in a close future, and could be used in various situations.

3 - if you want a single organism that create offsrping and evolve without any interaction with a male, it is absolutely possible. There exist several mode of "duplication" of the organisms. By Fission, you can separate the body into 2 (usually for microbes), Division and regenaration (in that case you have the same genome accros multiple generations), but if you want to create evolution and diversification within your species, you probably need a sexual species that can use auto-fertilization. Some intringing lizards and frogs species do it :) The change of sex mostly depend on environmental conditions, such as temperature. I suggest you to google evolutionary website to check the strange sexual reproduction modes.